Accuracy of Prescription Claims Data in Identifying Truly Nonadherent Patients

Physician and patient adherence in hypertension trials: a point of view on an important issue to resolve

INTRODUCTION

Randomized controlled trials (RCTs) are important sources of evidence that strongly influence guidelines for patient management, including for elevated blood pressure in adults.

AREAS COVERED

Critical questions regarding the interpretation of hypertension trial results have recently increased, especially for concerns over methodology. In particular, investigator adherence to the protocol and patient adherence to investigational drugs are often far from optimal. These issues may be ignored or underreported because physicians' behavior during trials is often not monitored and patients' medication adherence is neither measured adequately nor reported or analyzed in the final report or in the publication. This situation may lead to misinterpretations of study results and misevaluations of the safety and efficacy profile of new drugs. In this short review, the problem of measuring, reporting, and analyzing drug adherence in RCTs is discussed and illustrated with several examples in the field of hypertension.

EXPERT OPINION

The main conclusion is that drug adherence should always be measured in clinical trials, possibly with more than one method. In addition, prespecified analyses of adherence data should be included in the statistical plan of all trials to improve their overall quality.

Comparison of measures of medication adherence from pharmacy dispensing and insurer claims data

OBJECTIVE

Medication nonadherence is linked to worsened clinical outcomes and increased costs. Existing system-level adherence interventions rely on insurer claims for patient identification and outcome measurement, yet suffer from incomplete capture and lags in data acquisition. Data from pharmacies regarding prescription filling, captured in retail dispensing, may be more efficient.

DATA SOURCES

Pharmacy fill and insurer claims data.

STUDY DESIGN

We compared adherence measured using pharmacy fill data to adherence using insurer claims data, expressed as proportion of days covered (PDC) over 12 months. Agreement was evaluated using correlation/validation metrics. We also explored the relationship between adherence in both sources and disease control using prediction modeling.

DATA EXTRACTION METHODS

Large pragmatic trial of cardiometabolic disease in an integrated delivery network.

PRINCIPAL FINDINGS

Among 1113 patients, adherence was higher in pharmacy fill (mean = 50.0%) versus claims data (mean = 47.4%), although they had moderately high correlation (R = 0.57, 95% CI: 0.53-0.61) with most patients (86.9%) being similarly classified as adherent or nonadherent. Sensitivity and specificity of pharmacy fill versus claims data were high (0.89, 95% CI: 0.86-0.91 and 0.80, 95% CI: 0.75-0.85). Pharmacy fill-based PDC predicted better disease control slightly more than claims-based PDC, although the difference was nonsignificant.

CONCLUSIONS

Pharmacy fill data may be an alternative to insurer claims for adherence measurement.

Patients discharged from a fracture liaison service still require follow-up and bone health advice

Fracture liaison services (FLSs) were established to address the well-recognised gap in bone health management after a fragility fracture. However, it is unclear what happens to patients after discharge from an FLS. Our study suggests FLSs should include a patient bone health education session and a follow-up telephone call 12-18 months post-discharge to optimise management, in particular, to assess therapy adherence and to reinforce bone health advice.

PURPOSE

While fracture liaison services (FLSs) have improved bone health management following fragility fracture, it is unclear what happens to patients following discharge from these services. We sought to determine patient self-reported medication adherence and the need for bone-specific health advice ≥ 12 months following discharge from one of the first FLSs in Australia.

METHODS

Patients were contacted by telephone ≥ 12 months following discharge from the Coffs Fracture Prevention Clinic (CFPC)/FLS to determine if the patient was still taking prescribed bone protective therapy (BPT). Bone health advice was provided, if appropriate, during the telephone interview.

RESULTS

Of the 516 consecutive patients seen in CFPC from July 2012-December 2018, 326 (63.2%) were assessed and discharged from the clinic. One hundred and two patients (19.8%) were lost to follow-up/uncontactable. Of 190 patients commenced on BPT at CFPC and who were discharged ≥ 12 months prior, 141 (74.2%) self-reported adherence with BPT. Bone health advice was required during the telephone call in 60/190 (31.6%) of these patients. Of the 141 adherent patients, 40 (28.4%) had attended a bone health education session, compared to 4/49 (8.2%) patients in the non-adherent group (p = 0.004).

CONCLUSION

At 19 months following discharge from our FLS, self-reported adherence with treatment was 74%. One bone health education session at baseline was associated with increased treatment adherence. At time of telephone contact, one third of patients required further advice to optimise bone health.