Sutinen, S,Lahti, S,Nuttall, NM,Sanders, AE,Steele, JG,Allen, PF,Slade, GD

2007

June

European Journal of Oral Sciences

Effect of a 1-month vs. a 12-month reference period on responses to the 14-item Oral Health Impact Profile

Validated

()

dental health surveys epidemiologic measurement oral health-related quality of life QUALITY-OF-LIFE

115

246

249

The length of the reference period used in surveys of subjective oral health may have a marked influence on the responses obtained. We aimed to evaluate the effect of a 1-month (RP-1) vs. a 12-month (RP-12) reference period in the Oral Health Impact Pro. le (OHIP-14) questionnaire. Using a randomized cross-over design, RP-1 and RP-12 OHIP-14 questionnaires were administered, 1 month apart, to two samples of Finnish adults, namely people awaiting orthognathic surgery (n = 104) and non-patient workers (n = 111). The effect of the reference period was computed by subtracting RP-1 OHIP-14 severity scores from RP-12 OHIP-14 severity scores (Delta RP). Potential order effects were assessed by comparing Delta RP between groups completing the RP-1 vs. the RP-12 questionnaire first. Mean OHIP-14 severity scores were slightly higher when the RP-12 questionnaire was administered first, but mean Delta RP values were below the value of 2.5 considered clinically meaningful, and all 95% confidence intervals for Delta RP included zero. No order effects in the OHIP-14 severity scores were observed. Therefore, although a standardized reference period of 12 months is recommended, in population surveys the use of a shorter reference period does not appear to influence responses.