Evidence of Selection Bias and Non-Response Bias in Patient Satisfaction Surveys

Patient satisfaction surveys are increasingly utilized to measure the patient experience and as a tool to assess the quality of care delivered by medical providers. Press Ganey (PG) is the largest provider of tools for patient satisfaction measurement and analysis. The purpose of this study was to determine if patient satisfaction surveys were subject to selection and/ or nonresponse bias.

Patients seen in an outpatient academic orthopedic clinic were included in this retrospective cohort study. Demographic data included age, race, gender, marital status, primary payer, and native language. All surveys were administered by PG Associates per internal protocols adhering to exclusion criteria within the institutional contract with PG Associates.

3.5% of outpatient encounters generated PG survey data, which were generated by 9.1% of all patients evaluated. The population of patients who were administered as well as patients who responded to the patient satisfaction survey represented a unique population with regards to age, race, gender, marital status, insurance status, and native language.

Demographically, patients who were administered and patients who responded to PG surveys differed from the overall population of patients seen in an outpatient orthopedic setting, evidencing both selection and non-response bias. Because of these differences, and considering the small number of survey returned, caution should be exercised when interpreting and applying these data.Level of Evidence: III.