Background

Although controversial, most studies examining the relationship of body mass index (BMI) with mortality in diabetes suggest a paradox: the lowest risk category is above normal weight, versus normal weight in nondiabetic persons. One proposed explanation is greater morbidity of diabetes in normal weight persons. If this were so, it would suggest a health care utilization paradox in diabetes, paralleling the mortality paradox, yet no studies have examined this issue.

Objective

To compare the relationship of BMI with health care utilization in diabetic versus nondiabetic persons.

Design

Population-based cross-sectional study.

Subjects

Adults in the 2000-2011 Medical Expenditures Panel Surveys (N=120,389).

Measures

Total health care expenditures, hospital utilization (≥1 admission), and emergency department utilization (≥1 visit). BMI (kg/m) categories were: <20 (underweight); 20 to <25 (normal); 25 to <30 (overweight); 30 to <35 (obese); and ≥35 (severely obese). Adjustors were age, sex, race/ethnicity, income, health insurance, education, smoking, co-morbidity, urbanicity, region, and year.

Results

Among diabetic persons, adjusted mean total health care expenditures were significantly lower in obese versus normal weight persons ($1314, 95% confidence interval [CI], $513-$2115; P=0.001). By contrast, among nondiabetic persons, total expenditures were nonsignificantly higher in obese versus normal weight persons (-$229, 95% CI, -$460 to $2; P=0.052). Findings for hospital and emergency department utilization exhibited similar patterns.

Conclusions

Normal weight diabetic persons used substantially more health care than their overweight and obese counterparts, a difference not observed in nondiabetic persons. These differences support the plausibility of a BMI mortality paradox related to greater morbidity of diabetes in normal weight than in heavier persons.

Background

Patient experience measures are widely used to compare performance at the individual physician level.

Objective

To assess the impact of unmeasured patient characteristics on visit-level patient experience measures and the sample sizes required to reliably measure patient experience at the primary care physician (PCP) level.

Design

Repeated cross-sectional design.

Setting

Academic family medicine practice in California.

Participants

One thousand one hundred forty-one adult patients attending 1319 visits with 56 PCPs (including 45 resident and 11 faculty physicians).

Measurements

Post-visit patient experience surveys including patient measures used for standard adjustment as recommend by the Consumer Assessment of Healthcare Providers and Systems (CAHPS) Consortium and additional patient characteristics used for expanded adjustment (including attitudes toward healthcare, global life satisfaction, patient personality, current symptom bother, and marital status).

Results

The amount of variance in patient experience explained doubled with expanded adjustment for patient characteristics compared with standard adjustment (R² = 20.0% vs. 9.6%, respectively). With expanded adjustment, the amount of variance attributable to the PCP dropped from 6.1% to 3.4% and the required sample size to achieve a reliability of 0.90 in the physician-level patient experience measure increased from 138 to 255 patients per physician. After ranking of the 56 PCPs by average patient experience, 8 were reclassified into or out of the top or bottom quartiles of average experience with expanded as compared to standard adjustment [14.3% (95% CI: 7.0-25.2%)].

Conclusions

Widely used methods for measuring PCP-level patient experience may not account sufficiently for influential patient characteristics. If methods were adapted to account for these characteristics, patient sample sizes for reliable between-physician comparisons may be too large for most practices to obtain.