Subject:
Esophageal pH Monitoring
Description:
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IMPORTANT NOTE:
The purpose of this policy is to provide general information applicable to the administration of health benefits that Horizon Blue Cross Blue Shield of New Jersey and Horizon Healthcare of New Jersey, Inc. (collectively “Horizon BCBSNJ”) insures or administers. If the member’s contract benefits differ from the medical policy, the contract prevails. Although a service, supply or procedure may be medically necessary, it may be subject to limitations and/or exclusions under a member’s benefit plan. If a service, supply or procedure is not covered and the member proceeds to obtain the service, supply or procedure, the member may be responsible for the cost. Decisions regarding treatment and treatment plans are the responsibility of the physician. This policy is not intended to direct the course of clinical care a physician provides to a member, and it does not replace a physician’s independent professional clinical judgment or duty to exercise special knowledge and skill in the treatment of Horizon BCBSNJ members. Horizon BCBSNJ is not responsible for, does not provide, and does not hold itself out as a provider of medical care. The physician remains responsible for the quality and type of health care services provided to a Horizon BCBSNJ member.
Horizon BCBSNJ medical policies do not constitute medical advice, authorization, certification, approval, explanation of benefits, offer of coverage, contract or guarantee of payment.
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Esophageal pH monitoring, using wired or wireless devices, can record the pH of the lower esophagus for a period of several days. Impedance pH monitoring measures electrical impedance in the esophagus to evaluate reflux episodes concurrent with changes in pH. These tests are used for certain clinical indications in the evaluation of gastroesophageal reflux disease (GERD).
Populations | Interventions | Comparators | Outcomes |
Individuals:
- With gastroesophageal reflux disease
| Interventions of interest are:
- Catheter-based pH monitoring
| Comparators of interest are:
| Relevant outcomes include:
- Test validity
- Symptoms
- Functional outcomes
|
Individuals:
- With gastroesophageal reflux disease
| Interventions of interest are:
| Comparators of interest are:
- Catheter-based pH monitoring
- Standard of care
| Relevant outcomes include:
- Test validity
- Symptoms
- Functional outcomes
|
Individuals:
- With gastroesophageal reflux disease
| Interventions of interest are:
| Comparators of interest are:
- Catheter-based pH monitoring
- Standard of care
| Relevant outcomes include:
- Test validity
- Symptoms
- Functional outcomes
|
BACKGROUND
Gastroesophageal Reflux Disease
Acid reflux is the cause of heartburn and acid regurgitation esophagitis, which can lead to esophageal stricture. Acid reflux can also cause or contribute to some cases of asthma, posterior laryngitis, chronic cough, dental erosions, chronic hoarseness, pharyngitis, subglottic stenosis or stricture, nocturnal choking, and recurrent pneumonia.
Diagnosis
Gastroesophageal reflux disease is most commonly diagnosed by clinical evaluation and treated empirically with a trial of medical management. For patients who do not respond appropriately to medications, or who have recurrent chronic symptoms, endoscopy is indicated to confirm the diagnosis and assess the severity of reflux esophagitis. In some patients, endoscopy is nondiagnostic, or results are discordant with the clinical evaluation (in these cases, further diagnostic testing may be of benefit).
Monitoring
Esophageal monitoring is done using a tube with a pH electrode attached to its tip, which is then passed into the esophagus to approximately 5 cm above the upper margin of the lower esophageal sphincter. The electrode is attached to a data recorder worn on a waist belt or shoulder strap. Every instance of acid reflux, as well as its duration and pH, is recorded over a 24-hour period. Wireless pH monitoring is achieved using endoscopic or manometric guidance to attach the pH measuring capsule to the esophageal mucosa using a clip. The capsule records pH levels for up to 96 hours and transmits them via radiofrequency telemetry to a receiver worn on the patient’s belt. Data from the recorder are uploaded to a computer for analysis by a nurse or doctor.
Another technology closely related to pH monitoring is impedance pH monitoring, which incorporates pH monitoring with measurements of impedance, a method of measuring reflux of liquid or gas of any pH. Multiple electrodes are placed along the length of the esophageal catheter. The impedance pattern detected can determine the direction of flow and the substance (liquid or gas). Impedance monitoring can identify reflux events in which the liquid is only slightly acidic or nonacidic.
Regulatory Status
Esophageal pH electrodes are considered class I devices by the U.S. Food and Drug Administration (FDA) and are exempt from 510(k) requirements. A catheter-free, temporarily implanted device (Bravo™ pH Monitoring System; Medtronic, now Given Imaging) was cleared for marketing by the FDA through the 510(k) process for the purpose of “gastroesophageal pH measurement and monitoring of gastric reflux in adults and children from 4 years of age.”
Several wireless and catheter-based (wired) esophageal pH monitoring devices have been cleared for marketing by the FDA through the 510(k) process. Examples include the Bravo™ pH Monitoring System (Given Imaging), the Sandhill Scientific PediaTec™ pH Probe (Sandhill Scientific), the ORION II Ambulatory pH Recorder (MMS, Medical Measurement Systems), and the TRIP CIC Catheter (Tonometrics). FDA product code: FFT.
Related Policies
Policy:
(NOTE: For Medicare Advantage, Medicaid and FIDE-SNP, please refer to the Coverage Sections below for coverage guidance.)
1. Esophageal pH monitoring using a catheter-based device or a catheter-free, wireless device (Bravo pH Monitoring System) is considered medically necessary for any of the following indications in adults and children or adolescents able to report symptoms: (NOTE: Esophageal pH monitoring systems should be used in accordance with U.S. Food and Drug Administration‒approved indications and age ranges.)
- To document abnormal esophageal acid exposure in an endoscopy-negative member being considered for surgical antireflux repair (pH study done after withholding antisecretory drug regimen for 1 week or longer);
- To evaluate members after antireflux surgery who are suspected of having ongoing abnormal reflux (pH study done after withholding antisecretory drug regimen for 1 week or longer);
- To evaluate members with either normal or equivocal endoscopic findings and reflux symptoms that are refractory to proton pump inhibitor therapy (pH study done after withholding antisecretory drug regimen for 1 week or longer if the study is done to confirm excessive acid exposure or while taking the antisecretory drug regimen if symptom-reflux correlation is to be scored);
- To detect refractory reflux in members with chest pain after cardiac evaluation using a symptom reflux association scheme, preferably the symptom association probability calculation (pH study done withholding PPI therapy for at least 1 week after a trial of proton pump inhibitor therapy for at least 4 weeks);
- To evaluate a member with suspected otolaryngologic manifestations (laryngitis, pharyngitis, chronic cough) of gastroesophageal reflux disease after symptoms have failed to respond to at least 4 weeks of proton pump inhibitor therapy (pH study done while the member continues taking their antisecretory drug regimen to document the adequacy of therapy); or
- To document concomitant gastroesophageal reflux disease in an adult onset, nonallergic asthmatic suspected of having reflux-induced asthma (pH study done after withholding antisecretory drug regimen for 1 week or longer).
2. Esophageal pH monitoring using a catheter-based device or a catheter-free, wireless device (Bravo pH Monitoring System) is also considered medically necessary in infants or children who are unable to report or describe symptoms of reflux with: (NOTE: Esophageal pH monitoring systems should be used in accordance with U.S. Food and Drug Administration‒approved indications and age ranges.)
- unexplained apnea;
- bradycardia;
- refractory coughing or wheezing, stridor, or recurrent choking (aspiration);
- persistent or recurrent laryngitis; and
- recurrent pneumonia.
3. Esophageal pH monitoring using a catheter-based device or a catheter-free, wireless device (Bravo pH Monitoring System) is considered investigational for all other indications including but not limited to the:
- detection or verification of reflux esophagitis (this is an endoscopic diagnosis);
- evaluation of alkaline reflux.
4. Catheter-based impedance-pH monitoring is not considered medically necessary.
Medicare Coverage:
Per NCD 100.3, 24-Hour Ambulatory Esophageal pH Monitoring is covered for patients who are suspected of having gastric reflux, when the patient presents diagnostic problems associated with atypical symptoms or the patient's symptoms are suggestive of reflux, but conventional tests have not confirmed the presence of reflux. For additional information and eligibility, refer to National Coverage Determination (NCD) for 24-Hour Ambulatory Esophageal pH Monitoring (100.3). Available to be accessed at CMS National Coverage Determinations (NCDs) Alphabetical Index search page: https://www.cms.gov/medicare-coverage-database/indexes/ncd-alphabetical-index.aspx
Medicaid Coverage:
For members enrolled in Medicaid and NJ FamilyCare plans, Horizon BCBSNJ applies the above medical policy.
FIDE SNP:
For members enrolled in a Fully Integrated Dual Eligible Special Needs Plan (FIDE-SNP): (1) to the extent the service is covered under the Medicare portion of the member’s benefit package, the above Medicare Coverage statement applies; and (2) to the extent the service is not covered under the Medicare portion of the member’s benefit package, the above Medicaid Coverage statement applies.
Policy Guidelines: (Information to guide medical necessity determination based on the criteria contained within the policy statements above.)
Manometry, when used for pH tip placement, should be considered part of the pH recording.
[RATIONALE: This policy was created in 1993 and has been updated regularly with searches of the MEDLINE database. The most recent literature update was performed through September 20, 2018.
Evidence reviews assess whether a medical test is clinically useful. A useful test provides information to make a clinical management decision that improves the net health outcome. That is, the balance of benefits and harms is better when the test is used to manage the condition than when another test or no test is used to manage the condition.
The first step in assessing a medical test is to formulate the clinical context and purpose of the test. The test must be technically reliable, clinically valid, and clinically useful for that purpose. Evidence reviews assess the evidence on whether a test is clinically valid and clinically useful. Technical reliability is outside the scope of these reviews, and credible information on technical reliability is available from other sources.
Catheter-Based pH Monitoring for Gastroesophageal Reflux Disease
Clinical Context and Test Purpose
The purpose of catheter-based pH monitoring in patients who have gastroesophageal reflux disease (GERD) is to inform a decision whether to proceed to appropriate treatment.
The question addressed in this policy is: Does the use of catheter-based pH monitoring improve the net health outcome in individuals with GERD?
The following PICO s were used to select literature to inform this review.
Patients
The relevant population of interest is individuals with GERD.
Interventions
The test being considered is catheter-based pH monitoring. Esophageal pH monitoring for 24 hours with catheter-based systems is primarily used in patients who have GERD that has not responded symptomatically to a program of medical therapy (including proton pump inhibitors); monitoring is also conducted in patients with refractory extra-esophageal symptoms.
Comparators
The following practice is currently being used to manage GERD: standard of care.
Outcomes
The general outcomes of interest are test validity, symptoms, and functional outcomes. Follow-up ranges over weeks to months for the outcomes of interest.
Study Selection Criteria
For the evaluation of clinical validity of the test, studies that meet the following eligibility criteria were considered:
·Reported on the accuracy of the marketed version of the technology (including any algorithms used to calculate scores)
·Included a suitable reference standard (describe the reference standard)
·Patient/sample clinical characteristics were described
·Patient/sample selection criteria were described.
Technical Reliability
Assessment of technical reliability focuses on specific tests and operators and requires review of unpublished and often proprietary information. Review of specific tests, operators, and unpublished data are outside the scope of this policy and alternative sources exist. This policy focuses on the clinical validity and clinical utility.
Clinically Valid
A test must detect the presence or absence of a condition, the risk of developing a condition in the future, or treatment response (beneficial or adverse).
There is no independent reference standard for GERD for specific populations. Traditional pH monitoring has been evaluated in patients with endoscopically diagnosed GERD, where it has been shown to be positive 77% to 100% of the time.1, However, in clinically defined but endoscopically negative patients, the test is positive from 0% to 71% of the time. In normal control populations, traditional pH monitoring is positive in 0% to 15% of subjects. Thus, the test is imperfectly sensitive and specific in patients with known presence or absence of disease. The current evidence for the diagnostic capability of catheter-based pH monitoring led Kahrilas and Quigley (1996), authors of a technical review, “…to conclude that ambulatory pH studies quantify esophageal acid exposure but that this has an imperfect correlation with reflux-related symptoms, esophageal sensitivity, or response to acid suppressive therapy.”1,
Although established technology, aspects of these catheter-based systems’ use as a diagnostic test for GERD are problematic, and thus make it difficult to determine its utility or the utility of potential alternative tests. Without a reference standard for GERD, it is difficult to compare the diagnostic test performance of different types of tests. While it is possible to determine the degree to which the 2 tests correlate, it is difficult to determine if one is better than the other.
Section Summary: Clinically Valid
Catheter-based pH monitoring systems correlate with symptoms of GERD or endoscopically defined GERD; however, without a true reference standard for clinical GERD, the diagnostic characteristics of catheter-based pH monitoring systems are uncertain.
Clinically Useful
A test is clinically useful if the use of the results informs management decisions that improve the net health outcome of care. The net health outcome can be improved if patients receive correct therapy, or more effective therapy, or avoid unnecessary therapy, or avoid unnecessary testing.
Direct Evidence
Direct evidence of clinical utility is provided by studies that have compared health outcomes for patients managed with and without the test. Because these are intervention studies, the preferred evidence would be from randomized controlled trials (RCTs).
No RCTs were identified that assessed the clinical utility of catheter-based pH testing for this population.
Chain of Evidence
Indirect evidence on clinical utility rests on clinical validity. If the evidence is insufficient to demonstrate test performance, no inferences can be made about clinical utility.
Because the clinical validity of catheter-based pH testing for GERD has not been established, a chain of evidence supporting the test’s clinical utility cannot be constructed.
Section Summary: Catheter-Based pH Monitoring for Gastroesophageal Reflux Disease
Positive pH monitoring tests correlate with endoscopically defined GERD and with GERD symptoms, but because there is no reference standard for clinical GERD, diagnostic characteristics cannot be determined. There are no studies of clinical utility showing improved outcomes, and the chain of evidence supporting the utility of the test is weak.
Wireless pH Monitoring for GERD
Clinical Context and Test Purpose
The purpose of wireless pH monitoring in patients who have GERD is to inform a decision whether to proceed to appropriate treatment.
The question addressed in this policy is: Does the use of wireless pH monitoring improve the net health outcome in individuals with GERD?
The following PICOs were used to select literature to inform this review.
Patients
The relevant population of interest is individuals with GERD.
Interventions
The test being considered is wireless pH monitoring.
Comparators
The following tests and practices are currently being used to manage GERD:catheter-based pH monitoring and standard of care.
Outcomes
The general outcomes of interest are test validity, symptoms, and functional outcomes. Follow-up ranges over weeks to months for the outcomes of interest.
Study Selection Criteria
For the evaluation of clinical validity of the test, the eligibility criteria considered are those outlined in indication 1.
Technical Reliability
Assessment of technical reliability focuses on specific tests and operators and requires review of unpublished and often proprietary information. Review of specific tests, operators, and unpublished data are outside the scope of this policy and alternative sources exist. This policy focuses on the clinical validity and clinical utility.
Clinically Valid
A test must detect the presence or absence of a condition, the risk of developing a condition in the future, or treatment response (beneficial or adverse).
Systematic Reviews
A systematic review and meta-analysis by Kessels et al (2017) was unable to compare the accuracy of wireless pH testing with standard catheter monitoring due to variability across studies.2,
A TEC Special Report (2006) assessed wireless esophageal pH monitoring.3, Six case series reviewed in the report demonstrated success rates of over 90% in completing a 48-hour pH study. Two studies that surveyed patients who received wireless pH monitoring and patients who received traditional catheter monitoring showed less discomfort, less disruption of daily activities, and higher overall satisfaction with the wireless test. Studies that evaluated test positivity in clinically diagnosed GERD cases and normal controls showed similar results (results were also similar in patients using traditional pH monitoring). Studies that directly compared the performance of traditional catheter and wireless pH monitoring in the same patients revealed a fairly close correlation between the 2 types of studies after correcting for calibration differences; however, the ideal cut-point for test positivity differed for the tests.
Cohort Studies
Studies published since the 2006 TEC Special Report have shown similar findings on the correlation between wireless pH monitoring and standard catheter monitoring. Hakanson et al (2009) evaluated simultaneous wireless and traditional pH testing in 92 patients.4, Wireless pH testing showed consistently lower estimates of acid exposure than traditional pH testing. The 2 techniques correlated (r2=0.66); however, the range between limits of agreement was wide. The techniques were concordant on the final diagnosis 82.1% of the time. Wenner et al (2007), in a study of 64 patients with GERD and 50 asymptomatic controls, showed a sensitivity of 59% to 65% when setting the specificity to 90% to 95%.5 The sensitivity of wireless monitoring was noted to be worse than other studies of traditional pH monitoring, but the patient population may have had less severe disease. A study by Schneider et al (2007) revealed a similar diagnostic performance of wireless and traditional pH monitoring.5,
Additional studies have replicated findings that a longer period of monitoring increases the proportion of positive tests. Grigolon et al (2011) showed that, in 51 patients receiving prolonged monitoring, the 96-hour test reduced the number of indeterminate tests from 11 to 5.6, In this particular study, comparison of outcomes for patients who received wireless monitoring, and a matched control group who received traditional catheter monitoring, showed similar outcomes and satisfaction. Garrean et al (2008) studied the use of 96-hour pH testing where during the first 2 days of monitoring, patients were off therapy, and during the second 2 days, they were prescribed proton pump inhibitors.7, As expected, during the second and third days, fewer patients showed reflux symptoms. It is difficult to determine from data analysis how such a testing protocol improves the diagnosis of GERD. Scarpulla et al (2007) attempted 96-hour monitoring in 83 patients.8, Monitoring for the full 96 hours was successful in 41% of patients. In them, the proportion showing some degree of pathologic acid exposure increased as monitoring time increased.
Some studies have attempted to support an argument that a longer monitoring time with a wireless monitor would result in a superior test performance;however, without a reference standard, or showing superior patient outcomes based on the longer test, such an argument cannot be made. The longer monitoring period usually results in a larger proportion of tests that are classified as positive, depending on the method of determining a positive test. Prakash and Clouse (2005) compared the diagnostic yield for a single day of monitoring with the complete 2 days of monitoring.9, They reported that the second day of recording time increased the proportion of subjects with symptoms by 6.8%. However, this study had several methodologic flaws. Ideally, a study that compares the diagnostic performance of an additional day of monitoring would require an independent reference standard or demonstration of improved patient outcomes when managing patients with a 1-day vs a 2-day study. In this study, the 2-day study was essentially considered the “reference test,” and there was no discussion of how the second day of monitoring was used to improve patient management in this heterogeneous group of patients. In addition, in their statistical analysis, the authors eliminated patients who did not report any symptoms during the testing period, thus deflating the denominator and inflating the yield of the additional day of testing. Finally, the 1-day test was essentially a component of the 2-day test, and thus the 2 monitoring periods were not independent, further limiting any comparison between them. A greater number of positive tests produced by a longer duration of the test is not evidence of a superior test.
Section Summary: Clinically Valid
Wireless pH monitoring systems correlate with symptoms of GERD or endoscopically defined GERD; however, without a true reference standard for clinical GERD, the diagnostic characteristics of this test are uncertain.
Clinically Useful
A test is clinically useful if the use of the results informs management decisions that improve the net health outcome of care. The net health outcome can be improved if patients receive correct therapy, or more effective therapy, or avoid unnecessary therapy, or avoid unnecessary testing.
Direct Evidence
Direct evidence of clinical utility is provided by studies that have compared health outcomes for patients managed with and without the test. Because these are intervention studies, the preferred evidence would be from RCTs.
No RCTs were identified that assessed the clinical utility of wireless pH testing for this population.
Chain of Evidence
Indirect evidence on clinical utility rests on clinical validity. If the evidence is insufficient to demonstrate test performance, no inferences can be made about clinical utility.
Because the clinical validity of wireless pH testing for GERD has not been established, a chain of evidence supporting the test’s clinical utility cannot be constructed.
Section Summary: Wireless pH Monitoring for GERD
Positive wireless pH monitoring tests correlate with endoscopically defined GERD and GERD symptoms, but because there is no reference standard for clinical GERD, diagnostic characteristics cannot be determined. Some studies have shown higher positive test rates with prolonged wireless monitoring compared with catheter-based pH monitoring, but the effect of this finding on patient outcomes is uncertain. There are no studies of clinical utility showing improved outcomes, and the chain of evidence supporting the utility of the test is weak.
Impedance pH Testing for GERD
Clinical Context and Test Purpose
The purpose of impedance pH monitoring in patients who have GERD is to inform a decision whether to proceed to appropriate treatment.
The question addressed in this policy is: Does the use of impedance pH testing improve the net health outcome in individuals with GERD?
The following PICOs were used to select literature to inform this review.
Patients
The relevant population of interest is individuals with GERD.
Interventions
The test being considered is impedance pH testing.
Comparators
The following tests and practices are currently being used to manage GERD:impedance pH monitoring and standard of care.
Outcomes
The general outcomes of interest are test validity, symptoms, and functional outcomes. Follow-up ranges over weeks to months for the outcomes of interest.
Study Selection Criteria
For the evaluation of clinical validity of the test, the eligibility criteria considered are those outlined in indication 1.
Technical Reliability
Assessment of technical reliability focuses on specific tests and operators and requires review of unpublished and often proprietary information. Review of specific tests, operators, and unpublished data are outside the scope of this policy and alternative sources exist. This policy focuses on the clinical validity and clinical utility.
Clinically Valid
A test must detect the presence or absence of a condition, the risk of developing a condition in the future, or treatment response (beneficial or adverse).
Evidence on the use of impedance pH testing suffers from issues similar to the evaluation of wireless pH testing: lack of a reference standard and lack of evidence that shows improved patient outcomes. Many studies have argued that an increase in positive tests, or diagnostic yield, is by itself evidence that supports the validity of the test. However, the increase in positive tests, if it indicates increased sensitivity, may decrease specificity. The net effect on patient management and patient outcomes is uncertain.
Several studies have demonstrated a higher yield for positive tests when using impedance pH testing and identifying reflux events that are nonacidic or only weakly acidic (and thus would not be detected using pH testing alone).10,11,12, For example, Bajbouj et al (2007) studied 41 patients with atypical GERD symptoms with numerous tests.10, The test producing the highest number of positive findings was impedance pH testing. Bredenoord et al (2006) did a similar study in 48 patients.11, A higher proportion of subjects had positive tests when using impedance pH data (77%) than when using pH data alone (67%). A study by Mainie et al (2006) reported similar findings.12,
Studies have also examined performing impedance pH testing while patients are on acid-suppression therapy. Vela et al (2001) demonstrated that, during acid-suppressive therapy, the total number of reflux episodes is similar, but fewer episodes of acidic reflux occur.13,
Although impedance pH testing produces a higher number of positive tests, particularly compared with traditional or wired pH testing in the setting of concurrent acid-suppressive therapy, there is insufficient evidence that these test results are more accurate.
Section Summary: Clinically Valid
Impedance pH tests correlate with symptoms of GERD or endoscopically defined GERD; however, without a true reference standard for clinical GERD, the diagnostic characteristics of impedance pH testing are uncertain.
Clinically Useful
A test is clinically useful if the use of the results informs management decisions that improve the net health outcome of care. The net health outcome can be improved if patients receive correct therapy, or more effective therapy, or avoid unnecessary therapy, or avoid unnecessary testing.
Direct Evidence
Direct evidence of clinical utility is provided by studies that have compared health outcomes for patients managed with and without the test. Because these are intervention studies, the preferred evidence would be from RCTs.
No RCTs were identified that assessed the clinical utility of impedance pH testing for this population.
Chain of Evidence
Indirect evidence on clinical utility rests on clinical validity. If the evidence is insufficient to demonstrate test performance, no inferences can be made about clinical utility.
Because the clinical validity of impedance pH testing for GERD has not been established, a chain of evidence supporting the test’s clinical utility cannot be constructed.
Section Summary: Impedance pH Testing for GERD
Positive impedance pH tests correlate with endoscopically defined GERD and with GERD symptoms, but because there is no reference standard for clinical GERD, diagnostic characteristics cannot be determined. Some studies have shown higher positive test rates with impedance pH testing compared with pH testing alone, but the effect of this finding on patient outcomes is uncertain. There are no studies of clinical utility showing improved outcomes, and the chain of evidence supporting the utility of the test is weak.
Summary of Evidence
For individuals who have GERD who receive catheter-based pH monitoring, the evidence includes cross-sectional studies evaluating test performance in different populations. Relevant outcomes are test validity, symptoms, and functional outcomes. Positive pH monitoring tests correlate with endoscopically defined GERD and with GERD symptoms, but because there is no reference standard for clinical GERD, diagnostic characteristics cannot be determined. There are no studies of clinical utility showing improved outcomes, and the chain of evidence supporting the utility of the test is weak. The evidence is insufficient to determine that the technology improves health outcomes.
For individuals who have GERD who receive wireless pH monitoring, the evidence includes cross-sectional studies evaluating test performance and diagnostic yield in different populations. Relevant outcomes are test validity, symptoms, and functional outcomes. Positive wireless pH monitoring tests correlate with endoscopically defined GERD and GERD symptoms, but because there is no reference standard for clinical GERD, diagnostic characteristics cannot be determined. Some studies have shown higher positive test rates with prolonged wireless monitoring compared with catheter-based pH monitoring, but the effect of this finding on patient outcomes is uncertain. There are no studies of clinical utility showing improved outcomes, and the chain of evidence supporting the utility of the test is weak. The evidence is insufficient to determine that the technology improves health outcomes.
For individuals who have GERD who receive impedance pH testing, the evidence includes cross-sectional studies evaluating test performance and diagnostic yield in different populations. Relevant outcomes are test validity, symptoms, and functional outcomes. Positive impedance pH tests correlate with endoscopically defined GERD and with GERD symptoms, but because there is no reference standard for clinical GERD, diagnostic characteristics cannot be determined. Some studies have shown higher positive test rates with impedance pH testing compared with pH testing alone, but the effect of this finding on patient outcomes is uncertain. There are no studies of clinical utility showing improved outcomes, and the chain of evidence supporting the utility of the test is weak. The evidence is insufficient to determine that the technology improves health outcomes.
SUPPLEMENTAL INFORMATION
Clinical Input From Physician Specialty Societies and Academic Medical Centers
While the various physician specialty societies and academic medical centers may collaborate with and make recommendations during this process, through the provision of appropriate reviewers, input received does not represent an endorsement or position statement by the physician specialty societies or academic medical centers, unless otherwise noted.
In response to requests, input was received from 1 physician specialty society (2 reviewers) and 3 academic medical centers while this policy was under review for 2010. Input was mixed. Most reviewers indicated that the wireless device was more comfortable and allowed patients to do more varied activities during the recording. One reviewer cited problems with availability of the catheter-based systems. Moreover, most reviewers agreed that a link between wireless monitoring and improved health outcome had not been demonstrated.
Practice Guidelines and Position Statements
American College of Gastroenterology
The American College of Gastroenterology (ACG; 2007) released practice guidelines on esophageal reflux testing informed by a review of the literature up to 2006.14, Although the literature on wireless pH testing was extensively reviewed, the recommendations for testing made no distinction between wireless and traditional pH monitoring. An indirect endorsement of wireless monitoring might be inferred from a statement that a 48-hour study would produce a greater diagnostic yield from a symptom-association test. Symptom-association tests require statistical testing of the data, and a 48-hour test produces more data points. However, these statistical correlation tests are not perfect, because the guidelines stated that such measures “do not ensure a response to either medical or surgical antireflux therapies.” No studies were cited that indicated superior outcomes for patients for treatment guided by wireless pH testing vs traditional pH testing. The major advantage for the wireless system cited was patient tolerability.
Impedance pH monitoring was cited as “may be useful” (a lower category of recommendation than for pH monitoring) for evaluation of patients with insufficient response to medical therapy in whom documentation of nonacid reflux would alter clinical management. Moreover, ACG suggested that impedance monitoring has a greater yield for findings than pH monitoring when performed on proton pump inhibitor (PPI) therapy. The last statement of the guidelines specified that the implications of an abnormal impedance test are unproven at this time.
ACG (2013) published guidelines on the diagnosis and management of gastroesophageal reflux disease (GERD).15, The guidelines stated, “ambulatory esophageal reflux monitoring is indicated before consideration of endoscopic or surgical therapy in patients with nonerosive disease, as part of the evaluation of patients refractory to PPI therapy, and in situations when the diagnosis of GERD is in question.” This was a strong recommendation based on a low level of evidence. The ACG guidelines noted there was limited evidence and lack of clear consensus on how testing should be performed (eg, catheter-based pH, wireless pH, or impedance pH) for refractory GERD.
American Gastroenterological Association
The American Gastroenterological Association (2008) released a medical position statement and accompanying technical review on the management of GERD.16, Ambulatory impedance pH, catheter pH, and wireless pH monitoring were all supported as methods to evaluate patients with suspected GERD with otherwise normal endoscopy and no response to PPI therapy. The guidelines had a grade B recommendation, denoting fair evidence that the practice improves health outcomes. The guidelines additionally stated that the wireless pH monitor had superior sensitivity to catheter pH monitoring because of the extended period of recording.
However, as noted previously, an increase in positive tests has been documented in other reports as producing both increased sensitivity and decreased specificity relative to the reference standard used inthe particular study. Thus, taking into account both characteristics of diagnostic performance, it is unclear whether patient outcomes are improved.
National Institute for Health and Care Excellence
The National Institute for Health and Care Excellence (2006) released guidance on catheter-less esophageal pH monitoring.17, This guidance indicated catheter-less esophageal pH monitoring appears to be safe and effective and is commonly indicated for GERD symptoms refractory to PPIs and for GERD symptom recurrence after antireflux surgery.
The Institute (2015) published guidance on the diagnosis and management of GERD in children and young people.18, The recommendations specific to esophageal pH monitoring included:
“Consider performing an esophageal pH study (or combined esophageal pH and impedance monitoring if available) in infants, children and young people with:
·suspected recurrent aspiration pneumonia
·unexplained apneas
·unexplained non‑epilepticseizure‑like events
·unexplained upper airway inflammation
·dental erosion associated with a neurodisability
·frequent otitis media
·a possible need for fundoplication
·a suspected diagnosis of Sandifer’s syndrome.
Consider performing an esophageal pH study without impedance monitoring in infants, childrenandyoung people if, using clinical judgement, it is thought necessary to ensure effective acid suppression.”
U.S. Preventive Services Task Force Recommendations
Not applicable.
Ongoing and Unpublished Clinical Trials
A search of ClinicalTrials.gov in October 2018 did not identify any ongoing or unpublished trials that would likely influence this review.]
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Horizon BCBSNJ Medical Policy Development Process:
This Horizon BCBSNJ Medical Policy (the “Medical Policy”) has been developed by Horizon BCBSNJ’s Medical Policy Committee (the “Committee”) consistent with generally accepted standards of medical practice, and reflects Horizon BCBSNJ’s view of the subject health care services, supplies or procedures, and in what circumstances they are deemed to be medically necessary or experimental/ investigational in nature. This Medical Policy also considers whether and to what degree the subject health care services, supplies or procedures are clinically appropriate, in terms of type, frequency, extent, site and duration and if they are considered effective for the illnesses, injuries or diseases discussed. Where relevant, this Medical Policy considers whether the subject health care services, supplies or procedures are being requested primarily for the convenience of the covered person or the health care provider. It may also consider whether the services, supplies or procedures are more costly than an alternative service or sequence of services, supplies or procedures that are at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of the relevant illness, injury or disease. In reaching its conclusion regarding what it considers to be the generally accepted standards of medical practice, the Committee reviews and considers the following: all credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, physician and health care provider specialty society recommendations, the views of physicians and health care providers practicing in relevant clinical areas (including, but not limited to, the prevailing opinion within the appropriate specialty) and any other relevant factor as determined by applicable State and Federal laws and regulations.
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Index:
Esophageal pH Monitoring
Acid Reflux Test
Bravo pH Monitoring System
Catheter-Free Esophageal pH Monitoring System
Gastroesophageal Reflux Monitoring
Monitoring, Esophageal pH
pH Monitoring, Esophageal
Wireless Esophageal pH Monitoring
Catheter-Based Impedance pH Monitoring
Impedance pH Monitoring, Catheter-Based
References:
1. Kahrilas PJ, Quigley EM. Clinical esophageal pH recording: a technical review for practice guideline development. Gastroenterology. Jun 1996;110(6):1982-1996. PMID 8964428.
2. Kessels SJM, Newton SS, Morona JK, et al. Safety and efficacy of wireless pH monitoring in patients suspected of gastroesophageal reflux disease: a systematic review. J Clin Gastroenterol. Oct 2017;51(9):777-788. PMID 28877081.
3. Blue Cross and Blue Shield Assicaiton Technology Evaluation Center (TEC). Special Report: Wireless pH Monitoring. TEC Assessments. 2006;21(2).
4. Prakash C, Clouse RE. Value of extended recording time with wireless pH monitoring in evaluating gastroesophageal reflux disease. Clin Gastroenterol Hepatol. Apr 2005;3(4):329-334. PMID 15822037.
5. Schneider JH, Kramer KM, Konigsrainer A, et al. Ambulatory pH: monitoring with a wireless system. Surg Endosc. Nov 2007;21(11):2076-2080. PMID 17484003.
6. Hakanson BS, Berggren P, Granqvist S, et al. Comparison of wireless 48-h (Bravo) versus traditional ambulatory 24-h esophageal pH monitoring. Scand J Gastroenterol. 2009;44(3):276-283. PMID 19040176.
7. Scarpulla G, Camilleri S, Galante P, et al. The impact of prolonged pH measurements on the diagnosis of gastroesophageal reflux disease: 4-day wireless pH studies. Am J Gastroenterol. Dec 2007;102(12):2642-2647. PMID 17850412.
8. Garrean CP, Zhang Q, Gonsalves N, et al. Acid reflux detection and symptom-reflux association using 4-day wireless pH recording combining 48-hour periods off and on PPI therapy. Am J Gastroenterol. Jul 2008;103(7):1631-1637. PMID 18557714.
9. Grigolon A, Consonni D, Bravi I, et al. Diagnostic yield of 96-h wireless pH monitoring and usefulness in patients' management. Scand J Gastroenterol. May 2011;46(5):522-530. PMID 21366495.
10. Bajbouj M, Becker V, Neuber M, et al. Combined pH-metry/impedance monitoring increases the diagnostic yield in patients with atypical gastroesophageal reflux symptoms. Digestion. 2007;76(3-4):223-228. PMID 18174685.
11. Bredenoord AJ, Weusten BL, Timmer R, et al. Addition of esophageal impedance monitoring to pH monitoring increases the yield of symptom association analysis in patients off PPI therapy. Am J Gastroenterol. Mar 2006;101(3):453-459. PMID 16464226.
12. Mainie I, Tutuian R, Shay S, et al. Acid and non-acid reflux in patients with persistent symptoms despite acid suppressive therapy: a multicentre study using combined ambulatory impedance-pH monitoring. Gut. Oct 2006;55(10):1398-1402. PMID 16556669.
13. Vela MF, Camacho-Lobato L, Srinivasan R, et al. Simultaneous intraesophageal impedance and pH measurement of acid and nonacid gastroesophageal reflux: effect of omeprazole. Gastroenterology. Jun 2001;120(7):1599-1606. PMID 11375942.
14. Hirano I, Richter JE. ACG practice guidelines: esophageal reflux testing. Am J Gastroenterol. Mar 2007;102(3):668-685. PMID 17335450.
15. Katz PO, Gerson LB, Vela MF. Guidelines for the diagnosis and management of gastroesophageal reflux disease. Am J Gastroenterol. Mar 2013;108(3):308-328; quiz 329. PMID 23419381.
16. Kahrilas PJ, Shaheen NJ, Vaezi MF, et al. American Gastroenterological Association Medical Position Statement on the management of gastroesophageal reflux disease. Gastroenterology. Oct 2008;135(4):1383-1391, 1391 e1381-1385. PMID 18789939.
17. National Institute for Health and Care Excellence (NICE). Catheterless esophageal pH monitoring [IPG187]. 2006; https://www.nice.org.uk/Guidance/IPG187. Accessed September. 2019.
18. National Institute for Health and Care Excellence (NICE). Gastro-oesophageal reflux disease in children and young people: diagnosis and management [NG1]. 2015; https://www.nice.org.uk/guidance/ng1. Accessed September, 2019.
Codes:
(The list of codes is not intended to be all-inclusive and is included below for informational purposes only. Inclusion or exclusion of a procedure, diagnosis, drug or device code(s) does not constitute or imply authorization, certification, approval, offer of coverage or guarantee of payment.)
CPT*
HCPCS
* CPT only copyright 2019 American Medical Association. All rights reserved. CPT is a registered trademark of the American Medical Association.
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