A comparison of SF-36 and SF-12 composite scores and subsequent hospitalization and mortality risks in long-term dialysis patients.

BACKGROUND AND OBJECTIVES: The Short Form 12 (SF-12) has not been validated for long-term dialysis patients. The study compared physical and mental component summary (PCS/MCS) scores from the SF-36 with those from the embedded SF-12 in a national cohort of dialysis patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: All 44,395 patients who had scorable SF-36 and SF-12 from January 1, 2006, to December 31, 2006, and were treated at Fresenius Medical Care, North America facilities were included. Death and first hospitalization were followed for up to 1 year from the date of survey. Correlation and agreement were obtained between PCS-36 and PCS-12 and MCS-36 and MCS-12; then Cox models were constructed to compare associated hazard ratios (HRs) between them. RESULTS: Physical and mental dimensions both exhibited excellent intraclass correlation coefficients of 0.94. Each incremental point for both PCS-12 and PCS-36 was associated with a 2.4% lower adjusted HR of death and 0.4% decline in HR for first hospitalization (both P < 0.0001). Corresponding improvement in HR of death for each MCS point was 1.2% for MCS-12 and 1.3% for MCS-36, whereas both had similar 0.6% lower HR for hospitalization per point (all P < 0.0001). CONCLUSIONS: The use of the SF-12 alone or as part of a larger survey is valid in dialysis patients. Composite scores from the SF-12 and SF-36 have similar prognostic association with death and hospitalization risk. Prospective longitudinal studies of SF-12 surveys that consider responsiveness to specific clinical, situational, and interventional changes are needed in this population.

Association between achievement of hemodialysis quality-of-care indicators and quality-of-life scores.

BACKGROUND: Incremental achievement of quality indicator goals has been associated with progressive improvement in mortality and hospitalization risk in hemodialysis (HD) patients. STUDY DESIGN: Descriptive cross-sectional study. SETTING & PARTICIPANTS: All 33,879 HD patients treated at Fresenius Medical Care North America facilities for >90 days with scorable 36-Item Short Form Health Survey responses from January 1, 2006, to December 31, 2006. PREDICTOR: We hypothesized that achieving up to 5 HD goals before the survey (albumin >or= 4.0 g/dL, hemoglobin of 11-12 g/dL, equilibrated Kt/V >or= 1.2, phosphorus of 3.5-5.5 mg/L, and absence of HD catheter) results in better self-reported quality of life (QoL). OUTCOMES & MEASUREMENTS: Distributions of Physical and Mental Component Summary (PCS/MCS) scores within and across quality indicator categories determined during the prior 90 days from survey date (compared using analysis of covariance and linear regression models, with adjustment for case-mix and each of the quality indicators). RESULTS: Incremental achievement of up to 5 goals was associated with progressively higher PCS and MCS scores (both P for trend < 0.001). Compared with patients meeting all 5 goals (n = 4,208; reference group), case-mix-adjusted PCS score was lower by 1.8 point with only 4 goals met (n = 11,785), 3.4 points for 3 goals (n = 10,906), 4.9 points for 2 goals (n = 5,119), 5.9 points for 1 goal (n = 1,592), and 7.8 points in the 269 patients who failed to meet any goal (each P < 0.001 vs the reference group). The corresponding decreases in case-mix-adjusted MCS scores were 1.0 point for 4 goals met, 1.7 point for 3 goals, 2.3 points for 2 goals, 3.0 points for 1 goal, and 4.7 points with no goal met, with each P < 0.001 compared with the MCS score from patients who achieved all 5 goals. LIMITATIONS: Potential residual confounding from unmeasured covariates. CONCLUSION: Patients progressively meeting more quality goals report incrementally better QoL. Further studies are needed to determine whether prospective achievement of quality goals will result in improved QoL for HD patients.