Evidence of non-response bias in the Press-Ganey patient satisfaction survey

Measures of patient satisfaction have gained prominence in recent years as changes to the American health care system have led to the incorporation of such metrics into reimbursement models. The response rate for widely-used outpatient satisfaction metrics and variables influencing the probability of survey nonresponse remain largely unknown.

We reviewed all unique adult patients (16,779) who completed an outpatient encounter in the Department of Orthopaedic surgery at our academic institution from 1/1/13 to 10/24/13. Survey data was linked to each clinic visit, and patient factors including age, sex, insurance type, zip code, and orthopaedic subspecialty visited were recorded. The overall survey response rate was calculated. Logistic regression was performed, and unadjusted and adjusted odds ratios of patients' probability of responding to the Press-Ganey survey were calculated.

Two thousand seven hundred sixty two (16.5 %) of individuals completed a Press-Ganey patient satisfaction survey and 14017 patients did not respond. For those patients considered responders, 906 patients (32.8 %) did not complete all the survey items. Among these 906 patients, the mean number of missing items was 2.24 (Standard Deviation SD: 2.19). Age, sex, insurance type, and orthopaedic subspecialty were all found to be associated with the odds of responding to our patient satisfaction survey. Advancing age increased the odds of responding to the survey (Adjusted Odds Ratio (OR) = 3.396 for ≥65 vs. 18-29, p < 0.001). Several variables were associated with a decreased odds of survey response, and included male sex (Adjusted OR = 0.782 for Males vs. Females, p < 0.001), insurance type (Adjusted OR = 0.311 for Medicaid/Self-Pay vs. Private), and subspecialty type (Adjusted OR = 0.623 for Trauma vs. Adult Reconstruction).

The response rate to the Press-Ganey Medical Practice Survey of outpatient satisfaction is low in an orthopaedic outpatient population, and furthermore, is impacted by patient characteristics such as age, sex, insurance type, and type of orthopaedic subspecialist encountered. The findings of the present study should inform future non-response weighting procedures in this area. More research is needed to assess non-response bias-including follow-up studies of non-respondents-in order to more accurately measure of patient satisfaction.