Refining a health-related quality of life assessment strategy for solid organ transplant patients.

PURPOSE: The psychometric properties of generic health-related quality of life (HRQOL) assessment instruments were evaluated to identify a reliable, valid, and non-redundant battery to measure longitudinal outcomes in organ transplant patients.

METHODS

Objective functional performance and subjective HRQOL were assessed in 371 solid organ (liver, heart, kidney, lung) transplant patients using the Karnofsky scale, the SF-36 Health Survey (SF-36), and Psychosocial Adjustment to Illness Scale (PAIS). The surveys' internal-consistency reliability, criterion-related validity, and redundancy were tested.

RESULTS

The SF-36 mental (MCS) and physical components (PCS), and PAIS summary scales were internally consistent (all alpha > or = 0.83). Four out of seven PAIS scales (vocational, domestic, sexual, social) were collectively associated with the PCS (R = 0.65, P < 0.001), as was functional performance (r = 0.52, P < 0.001). Three PAIS scales (family, social, psychological distress) were associated with the MCS (R = 0.72, P < 0.001). Only the PAIS healthcare orientation (satisfaction) scale was not associated with the SF-36((R)). The relationship between functional performance and the PCS is stronger (r = 0.52, P < 0.001) than with the MCS (r = 0.25, P < 0.001) and the PAIS global score (r = 0.37, P < 0.001).

CONCLUSIONS

The SF-36 and PAIS are internally consistent and exhibit divergent criterion-related validity but, with the exception of the PAIS healthcare orientation scale, are statistically redundant. The advantages of the SF-36 include wider use, more norms, and a lesser response burden. A transplant-specific patient satisfaction inventory was indicated and was developed.