Conditional and unconditional estimation of multidimensional quality of life after hematopoietic stem cell transplantation: A longitudinal follow-up of 415 patients

Emerging literature suggests that quality of life (QOL) after bone marrow t ransplantation is relatively good but is accompanied in some patients by a variety of residual difficulties. The studies supporting this finding, howe ver, have been somewhat limited in scale, scope, design, and analysis. We c omprehensively measured changes in multidimensional QOL in a 4-year longitu dinal follow-up of 415 adult patients who received hematopoietic stem cell transplants at Fred Hutchinson Cancer Research Center. Questionnaire packet s containing 271 items were mailed annually posttransplantation to patients ' homes. Standard methods of analysis yielded conditional estimates dependi ng on compliance and survival, whereas new, likelihood-based methods genera ted unconditional estimates applicable to the full intent-to-treat populati on. Typical QOL levels generally remained high over the entire study period . Most QOL functioning significantly improved over 4 years, with the remain der showing no important decrement. Although isolated problem areas, such a s sexual dissatisfaction, did emerge, the level of dysfunction for most phy sical and psychological scales remained below 30% of scale maxima. Broadly similar results were obtained for conditional estimation, which may contain an optimistic bias, and for unconditional estimation, which largely avoids the bias. Because concurrence was obtained between the 2 types of estimati on, we conclude that most patients really do experience good levels of QOL in the 4 years after transplantation. Although some problems can be anticip ated, typical patients can look forward to a QOL after transplantation that is broadly comparable to that of the normal population.