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


METHODS
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.
Lacson
Eduardo
E
Clinical Sciences, Epidemiology, and Research, Fresenius Medical Care, North America, Waltham, Massachusetts 02451-1457, USA. elacsonj@fmc-na.com
Xu
Jianglin
J
Lin
Shu-Fang
SF
Dean
Sandie Guerra
SG
Lazarus
J Michael
JM
Hakim
Raymond M
RM
D000203:Activities of Daily Living; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D019538:Health Care Surveys; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications / Q000175:diagnosis* / Q000401:mortality* / Q000628:therapy*; D008297:Male; D008603:Mental Health; D008875:Middle Aged; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D006435:Renal Dialysis / Q000009:adverse effects / Q000401:mortality*; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome