The Center provides expertise in designing, validating, and applying both generic and disease-targeted health related quality of life (HRQOL) instruments across several disease states. For example, the Center developed and tested the only multi-dimensional and validated instrument in chronic liver disease, the Liver Disease Quality of Life Instrument (LDQOL 1.0). In addition, the Center has conducted several studies measuring HRQOL in irritable bowel syndrome (IBS), chronic hepatitis C, chronic hepatitis B, and HIV, among other conditions.
The Center has particular expertise in defining the minimally clinically important difference, or "MCID," for HRQOL scales. This is important because there is a clear difference between "statistically significant" and "clinically relevant" differences in HRQOL. The US Food and Drug Administration currently requires justification for interpreting HRQOL differences generated from Phase III clinical trials that employ HRQOL endpoints. Without knowing the MCID of a HRQOL measure, there is no way to adequately interpret the results of such a trial. Members of the Center have refined a technique to retrospectively establish the MCID for existing HRQOL measures. For example, a recent publication established the MCID for the SF-36 as 4.2 points for patients with Hepatitis C [PDF Download - Spiegel et al. Hepatology 2005]. This value now forms the basis not only for defining power calculations for clinical trials in Hepatitis C, but also for following patients clinically by using HRQOL endpoints as part of everyday care.
Other recent HRQOL studies include an analysis that identified clinically significant determinants of HRQOL in IBS and dyspepsia, a study of HRQOL in patients co-infected with HIV and chronic hepatitis C, a comparison of HRQOL measurements in chronic liver disease, and an analysis to evaluate the impact of a "negative" diagnostic examination on HRQOL and reassurance in irritable bowel syndrome (IBS). Members of the Center have additional expertise in utility assessment (a HRQOL measure necessary to perform cost-utility analysis) using time trade-off, standard gamble, visual analog, and multi-attribute scale techniques. Moreover, the Center has incorporated utilities into several published decision analyses. In light of this experience, the Center is highly qualified to provide consultation in HRQOL instrument development and validation, utility elicitation, and incorporation of HRQOL into both clinical trials and health economic analyses.
