The 2011 Clinical Practice Survey was sent to a random stratified sample of professionally active optometrists in September 2011. The distribution population of the survey was identified from:
1) AOA membership records,
2) State board of optometry databases, and
3) National Provider Index database
Optometrists who were professionally active with a valid mailing address and currently employed in the profession of optometry comprised the survey population. The population used to determine sample size was 39,646 optometrists. A random stratified sample of 5,944 optometrists was selected, 3,000 invitations were sent to current AOA member optometrists and 2,944 were sent to non-AOA member optometrists. One reminder post card was mailed in October 2011 and data collection was completed in November 2011.
Survey participants were provided the option of completing the survey on paper forms or using an electronic invitation code to complete the survey online. Four out of five respondents (80%) completed the survey using the online survey tool.
The population was adjusted by removing optometrists who were retired, deceased, no longer practicing optometry, and those optometrists who were not locatable resulting in 589 completed responses and a final adjusted overall response rate of 12%. Although the overall adjusted response rate is unimpressive, the overall error level associated with the data was 4% at the 95% confidence interval.