Comparison of two methods in deriving short version of OHRQoL

Although a long health-related quality of life (HRQoL) measure provides more comprehensive data, some research settings do not permit its use; thus, most health-related quality of life measures develop a short form to provide a more efficient way of collecting data. There are several methods to shorten a HRQoL measure. The question is which is a better method? Objective: To compare two methods of developing short forms of the Malaysian Oral Health Impact Profile (OHIP-M) measure. Method: Cross sectional data obtained using the long form of the OHIP-M was used to produce two types of OHIP-M short forms, derived using two different methods; namely regression and item frequency methods. Both short forms contained 14 items. These two forms were then compared in terms of their content, scores, reliability, validity and the ability to distinguish between groups. Results: Out of 14 items, only four were in common. The form derived from the frequency method contained more high prevalence items and higher scores than form derived from the regression method. Both methods produced a reliable and valid measure. However, the frequency method produced a measure which was slightly better in terms of distinguishing between groups. Conclusion: Both forms performed equally well when tested for their cross-sectional psychometric properties. However, the responsiveness of these measures was not tested in the present study. This could be one of the future research areas to determine which version is superior in terms of detecting change.