Variation Among Primary Care Physicians in 30-Day Readmissions

Abstract

Background: Whether readmission rates vary by primary care physician (PCP) is unknown, although federal policy holds PCPs accountable for reducing readmissions.

Objective: To determine whether 30-day readmission rates vary by PCP.

Design: Retrospective cohort study using marginal models and multilevel logistic regression with 100% of data on Texas Medicare claims from 2008 to 2015.

Setting: Texas.

Participants: Patients discharged alive between 1 January 2008 and 30 November 2015 who had a PCP in the prior year and whose PCP had at least 50 admissions in the study period.

Measurements: Readmission within 30 days of discharge. Follow-up visits with a PCP within 7 days of discharge were also measured.

Results: Between 2012 and 2015, the mean risk-standardized rate of 30-day readmissions was 12.9%. Of 4230 PCPs, 1 had a readmission rate that was significantly higher than the mean and none had a significantly lower rate. The 10th and 90th percentiles of PCP readmission rates were 12.4% and 13.4%, respectively, each only 0.5 percentage point different from the mean. The 99th percentile of PCP readmission rates was 14.0%, 1.1 percentage points higher than the mean. Detecting a 1.1-percentage point difference from the mean adjusted readmission rate would require more than 3500 admissions per PCP per year.

Limitations: Only fee-for-service Medicare patients in a single state were included. The authors could not account for confounders not included in Medicare databases or classify readmissions as avoidable.

Conclusion: Variation in readmission rates among PCPs is very low. Programs holding PCPs accountable for readmissions may prove ineffective.

Primary funding source: National Institutes of Health.

Figure 1.

Variation among 4230 PCPs in 30-day risk-standardized readmission rates. Readmission rate estimates were generated with a method used by the Centers for Medicare & Medicaid Services, which generates the ratio of the predicted to expected number of readmissions, multiplied by the national unadjusted rate, with bootstrapping (18). The readmission rates (adjusted means and 95% CIs) for each PCP are ranked from lowest to highest. The adjusted mean rate was 12.9% (dashed line). The minimum and maximum adjusted rates were 11.2% and 15.3%, respectively. The 10th percentile was 12.4% and the 90th was 13.4%, each only 0.5 percentage point from the mean. The 99th percentile rate was 14.0%, 1.1 percentage points above the mean. Only 1 PCP had a significantly higher readmission rate, indicated in red, and no PCP had a significantly lower rate. PCP = primary care physician.

Figure 2.

The number of admissions for each PCP (or group practice) that would result in 95% CIs that exclude a mean readmission rate of 13%, at different absolute differences from the mean rate. Differences ≤1 percentage point would require >4500 hospital discharges. PCP = primary care physician.

Figure 3.

Variation among 3603 PCPs in the risk-standardized rates of follow-up of their hospitalized patients within 7 days of discharge. Estimates were derived by a method similar to that used by the Centers for Medicare & Medicaid Services to measure readmission rates. We generated the ratio of the predicted to expected number of patients with follow-up for each PCP, multiplied by national rates, with bootstrapping (18). Adjusted rates of follow-up are ranked from lowest to highest. Rates and 95% CIs that significantly differ from the adjusted mean rate of 21.7% (dashed line) are shown in red. Of 3603 PCPs, 514 (14.3%) had 7-d follow-up rates significantly higher than the mean and 580 (16.1%) had rates significantly lower than the mean. The 10th percentile for the rates was 13.0%, and the 90th percentile was 31.2%. PCP = primary care physician.