Independence Estimating Equations for Controlled Clinical Trials with Small Sample Sizes

Integrating a Medical Home in an Outpatient Dialysis Setting: Effects on Health-Related Quality of Life

BACKGROUND

Integrating primary care has been proposed to reduce fragmented care delivery for patients with complex medical needs. Because of their high rates of morbidity, healthcare use, and mortality, patients with end-stage kidney disease (ESKD) may benefit from increased access to a primary care medical home.

OBJECTIVE

To evaluate the effect of integrating a primary care medical home on health-related quality of life (HRQOL) for patients with ESKD receiving chronic hemodialysis.

DESIGN

Before-after intervention trial with repeated measures at two Chicago dialysis centers.

PARTICIPANTS

Patients receiving hemodialysis at either of the two centers.

INTERVENTION

To the standard hemodialysis team (nephrologist, nurse, social worker, dietitian), we added a primary care physician, a pharmacist, a nurse coordinator, and a community health worker. The intervention took place from January 2015 through August 2016.

MAIN MEASURES

Health-related quality of life, using the Kidney Disease Quality of Life (KDQOL) measures.

KEY RESULTS

Of 247 eligible patients, 175 (71%) consented and participated; mean age was 54 years; 55% were men and 97% were African American or Hispanic. In regression analysis adjusted for individual visits with the medical home providers and other factors, there were significant improvements in four of five KDQOL domains: at 12 and 18 months, the Mental Component Score improved from baseline (adjusted mean 49.0) by 2.64 (p = 0.01) and 2.96 (p = 0.007) points, respectively. At 6 and 12 months, the Symptoms domain improved from baseline (adjusted mean = 77.0) by 2.61 (p = 0.02) and 2.35 points (p = 0.05) respectively. The Kidney Disease Effects domain improved from baseline (adjusted mean = 72.7), to 6, 12, and 18 months by 4.36 (p = 0.003), 6.95 (p < 0.0001), and 4.14 (p = 0.02) points respectively. The Physical Component Score improved at 6 months only.

CONCLUSIONS

Integrating primary care and enhancing care coordination in two dialysis facilities was associated with improvements in HRQOL among patients with ESKD who required chronic hemodialysis.

Rationale and design of a patient-centered medical home intervention for patients with end-stage renal disease on hemodialysis

In the U.S., more than 400,000 individuals with end-stage renal disease (ESRD) require hemodialysis (HD) for renal replacement therapy. ESRD patients experience a high burden of morbidity, mortality, resource utilization, and poor quality of life (QOL). Under current care models, ESRD patients receive fragmented care from multiple providers at multiple locations. The Patient-Centered Medical Home (PCMH) is a team approach, providing coordinated care across the healthcare continuum. While this model has shown some early benefits for complex chronic diseases such as diabetes, it has not been applied to HD patients. This study is a non-randomized quasi-experimental intervention trial implementing a Patient-Centered Medical Home for Kidney Disease (PCMH-KD). The PCMH-KD extends the existing dialysis care team (comprised of a nephrologist, dialysis nurse, dialysis technician, social worker, and dietitian) by adding a general internist, pharmacist, nurse coordinator, and a community health worker, all of whom will see the patients together, and separately, as needed. The primary goal is to implement a comprehensive, multidisciplinary care team to improve care coordination, quality of life, and healthcare use for HD patients. Approximately 240 patients will be recruited from two sites; a non-profit university-affiliated dialysis center and an independent for-profit dialysis center. Outcomes include (i) patient-reported outcomes, including QOL and satisfaction; (ii) clinical outcomes, including blood pressure and diet; (iii) healthcare use, including emergency room visits and hospitalizations; and (iv) staff perceptions. Given the significant burden that patients with ESRD on HD experience, enhanced care coordination provides an opportunity to reduce this burden and improve QOL.

Difference of two dependent sensitivities and specificities: Comparison of various approaches

In diagnostic studies, a new diagnostic test is often compared with a standard test and both tests are applied on the same patients, called paired design. The true disease state is in general given by the so-called gold standard (most reliable method for classification), which has to be known for all patients. The benefit of the new diagnostic test can be evaluated by sensitivity and specificity, which are in fact proportions. This means, for the comparison of two diagnostic tests, confidence intervals for the difference of the dependent estimated sensitivities and specificities are calculated. In the literature, many comparisons of different approaches can be found, but none explicitly for diagnostic studies. For this reason we compare 13 approaches for a set of scenarios that represent data of diagnostic studies (e.g., with sensitivity and specificity ≥0.8). With simulation studies, we show that the nonparametric interval with normal approximation can be recommended for the difference of two dependent sensitivities or specificities without restriction, the Wald interval with the limitation of slightly anti-conservative results for small sample sizes, and the nonparametric intervals with t-approximation, and the Tango interval with the limitation of conservative results for high correlations.