2 Minute Medicine Rewind December 19, 2016

Primary care physician volume and quality of diabetes care: a population-based cohort study

The volume of patients cared for by a primary physician may affect the quality of care that is delivered for chronic diseases. Diabetes mellitus (DM) is complex, interconnected disease process with many potential complications that requires regular clinical and biochemical monitoring, the prescription of appropriate medications, and time investment in patient education. In this population-based cohort study, 1,018,647 adults with diabetes receiving care from 9014 primary care physicians were followed up to assess the relationship between patient volume and quality of care. For the purposes of this study, the authors examined several patient-level indicators for quality of diabetes care. These indicators were broadly categorized into 3 domains: 1) appropriate disease monitoring and testing (eye examinations, hemoglobin A1c and low-density lipoprotein (LDL) cholesterol tests); 2) prescription of appropriate medications; and 3) adverse clinical outcomes, such as emergency department visits for hypoglycemia or hyperglycemia. Researchers found that higher overall ambulatory volume was significantly associated with lower rates of appropriate disease monitoring (p<0.001) and medication prescription (p<0.001). Diabetes-specific volume, however, was associated with better quality of care across all indicators (p<0.001). This study therefore shows that primary care physicians with high overall ambulatory volumes were more likely to deliver lower-quality diabetes care, while those with greater diabetes-specific experience were more likely to deliver higher-quality care.

Adult utilization of psychiatric drugs and differences by sex, age, and race

Based on the Survey on Drug Use and Health, the Substance Abuse and Mental Health Services Administration estimates that 11.5% of adults use prescription medication for “problems with emotions, nerves or mental health”. However, this survey does not offer specific information on the medications that are more commonly used, duration of use, or differences in use according to sex, age, race or ethnicity. In this cross-sectional study, the 2013 Medical Expenditure Panel Survey was used to characterize the use of prescription psychiatric drugs by 242 million US adults. Researchers found that 12.0% (95% CI 11.3% to 12.7%) of the study population reported filling one or more prescriptions for antidepressants, 8.3% (95% CI 7.7% to 8.9%) for anxiolytics, sedatives and hypnotics, and 1.6% (95% CI 1.4% to 1.8%) for antipsychotics. When examining differences in medication use across racial or ethnic groups, significant differences were found, with 20.8% of white adults reporting use, compared to 8.7% of Hispanic adults (OR 3.1, 95% CI 2.7 to 3.5). Compared to white adults, the rate of psychiatric drug use was also lower among black and Asian adults, however these differences were not statistically significant. The authors also found that use increased with age, with 25.1% of adults age 60-85 years using psychiatric drugs compared to 9.0% in patients age 18-39 years (OR 3.4, 95% CI 3.0 to 3.9). Women were also more likely to report using psychiatric drugs (OR 2.0, 95% CI 1.8 to 2.2). With respect to duration of use, the authors found that most psychiatric drug use was long-term, with 84.3% (95% CI 82.9% to 85.7%) having filled 3 or more prescriptions. This study therefore shows that certain racial/ethnic groups, women and older patients are more likely to use prescription psychiatric medications. Patients using prescription psychiatric medications are also likely to do so over a long-term period.

Five-year outcomes after off-pump or on-pump coronary-artery bypass grafting

Coronary artery bypass grafting (CABG) reduces the risk of death and complications due to severe coronary artery disease (CAD). Typically, this procedure is performed with the use of a cardiopulmonary bypass machine (on-pump CABG), however, it can also be performed on a beating heart (off-pump). The latter technique was developed to decrease the risk of perioperative complications and improve long-term outcomes. However, few studies have examined whether any differences in long-term outcomes exist. In this randomized controlled study, 4572 patients with CAD were randomly assigned to undergo off-pump or on-pump CABG and subsequently followed up to assess long-term outcomes of each procedure, including the risk of death, stroke, myocardial infarction, renal failure and repeat coronary revascularization with either CABG or percutaneous coronary intervention. The mean follow-up period was 4.8 years. Researchers found that there were no significant differences between the treatment arms with respect to the composite outcome, with 23.1% and 23.6% of patients from the off-pump and on-pump groups experienced one of the studied end-points, respectively (HR 0.98, 95% CI  0.87 to 1.10, p = 0.72). There were also no significant differences in the rates of individual outcomes. This study therefore shows that the rate of long-term adverse outcomes is similar among patients who undergo off-pump versus on-pump CABG.

Cetuximab plus chemoradiotherapy for HIV-associated anal carcinoma: a phase II AIDS malignancy consortium trial

Patients with HIV infection are at a significantly increased risk of developing squamous cell carcinoma of the anal canal (SCCAC) compared to the general population. Human papillomavirus (HPV) infection has been implicated in the development of SCCAC as the HPV-associated E5 protein amplifies the mitogenic signals mediated by the epidermal growth factor receptor (EGFR) broadly expressed in epithelial cancers. Cetuximab is an anti-EGFR antibody that has been found to prolong survival when used in combination with radiation therapy in patients with locally advanced squamous cell carcinoma of the oropharynx associated with HPV infection. In this clinical trial, 45 patients with SCCAC and HIV infection received chemoradiation (CRT) and eight once-weekly doses of concurrent cetuximab to determine whether the addition of cetuximab to CRT improves locoregional control of SCCAC. Locoregional failure (LRF) was defined as a progression or relapse of the disease in the anal canal, regional organs or lymph nodes. The study was designed to detect at least a 50% reduction in 3-year LRF rate, assuming a 35% LRF rate based on historical data. Researchers found that the 3-year LRF rate was 20% (95% CI 10% to 37%) by Kaplan-Meier estimate. The 3-year progression-free and overall survival rates according to Kaplan-Meier estimates were 72% (95% CI 56% to 84%) and 79% (95% CI 63% to 89%), respectively. This study therefore shows that the addition of cetuximab to CRT may result in less LRF in HIV-positive patients with SCCAC. However, with a LRF rate as high as 20%, there is still a need for more effective therapies.

Association of beta-blockers with functional outcomes, death, and rehospitalization in older nursing home residents after acute myocardial infarction

Beta-blockers have long been a mainstay of guideline-recommended care after acute myocardial infarction (AMI), with randomized trials demonstrating reductions in mortality in patients age 65-75 years. However, these medications are less often prescribed to older adults with functional impairment or multiple comorbidities, despite a paucity of data on adverse drug-related outcomes in frail or otherwise vulnerable older adults. In this cohort study, 15,720 nursing home residents that had experienced an AMI were followed up to assess the relationship between beta-blocker use after AMI and functional decline, death and rehospitalization in the first 90 days after AMI. Researchers found that beta-blocker users were more likely to experience functional decline (OR 1.14, 95% CI 1.02 to 1.28), corresponding to a number needed to harm (NNH) of 52 (95% CI 32 to 141). This association was increased among nursing home residents with moderate-severe cognitive impairment (OR 1.34, 95% CI 1.11 to 1.61) or severe functional dependency (OR 1.32, 95% CI 1.10 to 1.59). However, beta-blocker users were less likely to die (HR 0.74, 95% CI 0.67 to 0.83) and had similar rates of rehospitalization compared to non-users (HR 1.06, 95% CI 0.98 to 1.14). This study therefore shows that although beta-blocker users in this patient population confer a mortality benefit, the use of beta-blockers after AMI is associated with functional decline in older nursing home residents with moderate-severe cognitive impairment or functional impairment.

Image: PD

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