Patient-centered medical homes and oral anticoagulation therapy initiation

The Impact of Patient-Centered Medical Homes on Quality of Care and Medication Adherence in Patients with Diabetes Mellitus

BACKGROUND

Current evidence suggests that patient-centered medical homes (PCMHs) potentially increase overall quality of disease management, including preventive care. However, there are mixed findings regarding quality of diabetes care, and little evidence exists with respect to the effect of PCMHs on medication adherence in patients with diabetes.

OBJECTIVE

To investigate associations between PCMHs and process measures of diabetes care, as well as adherence to oral hypoglycemic agents (OHAs) in patients with diabetes in a nationally representative U.S.

SAMPLE

METHODS

Using the 2009-2013 longitudinal data files from the Medical Expenditure Panel Survey, adult diabetes patients were identified. Patients whose usual sources of care have all PCMH features at baseline (i.e., enhanced access after hours and online, shared decision making, and enhanced patient engagement) were categorized as the PCMH group, which was compared with patients without PCMH features. Process measures of diabetes care included ≥ 2 hemoglobin A1c tests and ≥ 1 cholesterol test, foot examination, dilated eye examination, and flu vaccination during 1 year of follow-up. Medication possession ratio (MPR) during follow-up was calculated for patients with OHAs without any insulin use, with MPR ≥ 80% considered to be adherent to OHAs. Univariate and multivariate regression models considering sampling strata and weights were used to examine the association between the PCMH and study outcomes.

RESULTS

A total of 3,334 patients with diabetes was identified, representing 61 million U.S. lives. The mean (SE) age was 61.6 (0.3) years, and 52.4% of patients were female. The mean (SE) years of having diabetes was 12.0 (0.2) years. Approximately 11.4% of the patients were categorized as the PCMH group at baseline, and only 3.6% of those patients remained in the PCMH group for 2 years. Of the diabetic patients identified, only 26.9% met all of the diabetes care process measure criteria defined in this study. A higher proportion of patients met process measure criteria in the PCMH group compared with the non-PCMH group (33.8% vs. 26.0%, respectively, P = 0.015). The weighted mean MPR (95% CI) of OHAs from the 2 groups were not statistically different (0.68, 95% CI = 0.63-0.74 for the PCMH group; 0.77, 95% CI = 0.72-0.82 for the non-PCMH group, P = 0.675), resulting in 47.4% of adherent patients in the study population. Overall, the PCMH group was associated with improvement in the process measures of diabetes care (adjusted odds ratios [OR] = 1.42, 95% CI = 1.06-1.91). The effect was greater among the patients who stayed in the PCMH group for 2 years (OR = 2.09, 95% CI = 1.27-3.45); were aged < 65 years (OR = 2.19, 95% CI = 1.47-3.28); or had less than 3 comorbid conditions (OR = 2.38, 95% CI = 1.46-3.88). However, the PCMH group was not associated with an increased adherence to OHAs (P = 0.495) or an increase in MPR (P = 0.570).

CONCLUSIONS

Patients with all PCMH features were associated with improvement in the process measures of diabetes care, but not in adherence to OHAs. Future studies should investigate the mechanism of PCMHs in overall quality of care, as well as medication adherence.

DISCLOSURES

No outside funding supported this study. The author reports no conflicts of interests.

Patient Perceptions of Patient-Centered Medical Home Characteristics and Satisfaction with Free Clinic Services

The patient-centered medical home (PCMH) is a model of health care delivery designed to improve patient health outcomes by increasing the effectiveness of primary care. The effectiveness of PCMH on vulnerable populations is still largely unknown. The purpose of this study was to examine the relationship between patient perceptions of PCMH characteristics and patient satisfaction among Spanish-speaking and non-Spanish-speaking patients receiving health care at free clinics. A self-administered survey was used to collect data in 2 free clinics in the United States in 2013. Patients were primarily young and female; 44% were Spanish speaking. Patient perceptions of PCMH characteristics were assessed using multi-item Consumer Assessment of Healthcare Providers and Systems scales developed by the Agency for Healthcare Research and Quality. Patient satisfaction was assessed as satisfaction with care received at the clinic and willingness to recommend the provider. Multivariate logistic regression modeled the association between PCMH components and these 2 patient satisfaction measures. In adjusted analyses among Spanish speakers, satisfaction with clinic care was associated with staff helpfulness (OR = 6.03, 95% CI = 1.87-19.46) and no perceived discrimination (OR = 2.55, 95% CI = 1.22-5.33). For non-Spanish speakers, provider communication and politeness significantly increased odds of satisfaction with clinic services. Provider communication was strongly associated with patients' intention to recommend the provider to others for both Spanish speakers and non-Spanish speakers (OR = 4.83, 95% CI = 1.35-17.24; OR = 5.42, 95% CI = 1.54-19.09, respectively). Findings suggest that interpersonal characteristics of providers and clinic staff are critical to patient satisfaction among vulnerable populations served by free clinics. Future studies should examine PCMH components and clinical outcomes among this population.

Moving towards best practice when using inverse probability of treatment weighting (IPTW) using the propensity score to estimate causal treatment effects in observational studies

The propensity score is defined as a subject's probability of treatment selection, conditional on observed baseline covariates. Weighting subjects by the inverse probability of treatment received creates a synthetic sample in which treatment assignment is independent of measured baseline covariates. Inverse probability of treatment weighting (IPTW) using the propensity score allows one to obtain unbiased estimates of average treatment effects. However, these estimates are only valid if there are no residual systematic differences in observed baseline characteristics between treated and control subjects in the sample weighted by the estimated inverse probability of treatment. We report on a systematic literature review, in which we found that the use of IPTW has increased rapidly in recent years, but that in the most recent year, a majority of studies did not formally examine whether weighting balanced measured covariates between treatment groups. We then proceed to describe a suite of quantitative and qualitative methods that allow one to assess whether measured baseline covariates are balanced between treatment groups in the weighted sample. The quantitative methods use the weighted standardized difference to compare means, prevalences, higher‐order moments, and interactions. The qualitative methods employ graphical methods to compare the distribution of continuous baseline covariates between treated and control subjects in the weighted sample. Finally, we illustrate the application of these methods in an empirical case study. We propose a formal set of balance diagnostics that contribute towards an evolving concept of ‘best practice’ when using IPTW to estimate causal treatment effects using observational data. © 2015 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Predictors of gastrointestinal bleeding among patients with atrial fibrillation after initiating dabigatran therapy

STUDY OBJECTIVES

To identify demographic and clinical risk factors associated with gastrointestinal (GI) bleeding among a large cohort of patients with atrial fibrillation (AF) who initiated dabigatran therapy for stroke prevention, and to describe patterns of subsequent anticoagulant use after occurrence of the GI bleeding event.

DESIGN

Retrospective cohort study.

DATA SOURCES

Large, nationwide United States commercial insurance database.

PATIENTS

A total of 21,033 patients with nonvalvular AF who initiated dabigatran between October 19, 2010, and December 31, 2012.

MEASUREMENTS AND MAIN RESULTS

We used multivariate Cox regression analysis to estimate the effect of baseline demographic and clinical characteristics on the probability of a GI bleeding event. Patterns of anticoagulation use after GI bleeding were also examined descriptively. Of the 21,033 patients receiving dabigatran, 446 (2.1%) experienced a GI bleed during follow-up. GI bleeding rates differed across many baseline characteristics. Male sex was associated with a lower risk (adjusted hazard ratio [aHR] 0.78, 95% confidence interval [CI] 0.64-0.95) of GI bleeding. Compared with patients younger than 55 years, those aged 55-64, 65-74, and 75 years or older yielded aHRs of 1.54 (95% CI 0.89-2.68), 2.72 (95% CI 1.59-4.65), and 4.52 (95% CI 2.68-7.64), respectively. Renal impairment (aHR 1.67, 95% CI 1.24-2.25), heart failure (aHR 1.25, 95% CI 1.01-1.56), alcohol abuse (aHR 2.57, 95%CI 1.52-4.35), previous Helicobacter pylori infection (aHR 4.75, 95% CI 1.93-11.68), antiplatelet therapy (aHR 1.49, 95% CI 1.19-1.88), and digoxin use (aHR 1.49, 95% CI 1.19-1.88) were also associated with an increased GI bleeding risk. Of the 446 patients who experienced a GI bleed, 193 (43.3%) restarted an anticoagulant, with most (65.8%) filling prescriptions for dabigatran; the mean time was 50.4 days until restarting any subsequent anticoagulant.

CONCLUSION

The risk of GI bleeding in patients receiving dabigatran is highly associated with increased age and cardiovascular, renal, and other comorbidities, even after adjusting for other factors. Fewer than 50% of patients restarted an anticoagulant after experiencing a GI bleed. Clinicians should continue to monitor for these risk factors or consider whether alternative therapies may be appropriate.