EVALUATION OF BIAS AND LOGISTICS IN A SURVEY OF ADULTS AT INCREASED RISK FOR ORAL HEALTH DECREMENTS

Objectives: Designing research to include sufficient respondents in gr oups at highest risk for oral health decrements can present unique cha llenges Our purpose was to evaluate bias and logistics in this survey of adults at increased risk for oral health decrements. Methods: We us ed a telephone survey methodology that employed both listed numbers an d random digit dialing to identify dentate persons 45 years old or old er and to oversample blacks, poor persons, and residents of nonmetropo litan counties. At a second stage, a subsample of the respondents to t he initial telephone screening was selected for further study, which c onsisted of a baseline in-person interview and a clinical examination. We assessed bias due to: (I) limiting the sample to households with t elephones, (2) using predominantly listed numbers instead of random di git dialing, and (3) nonresponse at two stages of data collection. Res ults: While this approach apparently created some biases in the sample , they were small in magnitude. Specifically, limiting the sample to h ouseholds with telephones biased the sample overall toward more female s, larger households, and fewer functionally impaired persons. Using p redominantly listed numbers led to a modest bias toward selection of p ersons more likely to be younger, healthier, female, have had a recent dental visit, and reside in smaller households. Blacks who were selec ted randomly at a second stage were more likely to participate in base line data gathering than their white counterparts. Comparisons of the data obtained in this survey with those from recent national surveys s uggest that this methodology for sampling high-risk groups did not sub stantively bias the sample with respect to two important dental parame ters, prevalence of edentulousness and dental care use, nor were concl usions about multivariate associations with dental care recency substa ntively affected. Conclusion: This method of sampling persons at high risk for oral health decrements resulted in only modest bias with resp ect to the population of interest.