NONRESPONSE BIAS IN A SURVEY OF ONTARIO DENTISTS INFECTION-CONTROL AND ATTITUDES CONCERNING HIV

Objective: This study investigated late response and nonresponse bias in an HIV-related survey of dentists. Methods: Questionnaires with ID numbers were mailed to all dentists in Ontario (N = 5,997) with additi onal mailings four and seven weeks later. Results: Proportionately mor e respondents who returned questionnaires less than four weeks after t he first mailing reported that they knowingly treated (P < .05) or wer e willing to treat HIV-infected patients (P < .05); that they had an a ccurate perception of risk of HIV infection after a needlestick injury (P < .01), and preferred not to refer HIV-infected patients (P < .01) . Linear extrapolation of cumulative percent responses indicated nonre sponse bias in terms of attitude and knowledge items; however, the mag nitude was low. Conclusions: The effects of late response and nonrespo nse bias on the results of this study were small. However, these resul ts cannot be generalized beyond the study population, and obtaining hi gh response rates and testing for nonresponse bias in surveys of attit udes related to HIV are recommended.