Health-related quality of life of multiple organ dysfunction patients: changes and comparison with normative population data

Introduction

Few studies analyzing health-related quality of life (HRQOL) in patients with multiple organ dysfunction (MOD) have used pre-ICU and follow-up data. Generic HRQOL instruments allow comparisons with normative population data and have recently demonstrated good reliability and validity when applied to intensive care unit (ICU) survivors [1].

Patients and methods

During June 1998 and May 1999 HRQOL was assessed in 318 consecutive adults admitted for > 24 hours to our non-coronary medical ICU. Baseline HRQOL measures were collected by interview during the first 24 hours of ICU stay and 6 months after admission using the Short Form (SF)-36 Health Survey, a generic health status measure that evaluates eight health domains that reflect physical and mental health. MOD was assessed using daily SOFA scores. MOD was defined as a SOFA total maximum score (TMS) of = 6 points. Baseline SF-36 data of ICU patients were compared with age and gender adjusted population norms obtained in the German Federal Health Survey 1998 (n = 6964). Changes in individual domains for each patient at follow-up were measured using normalized standard Z-scores (i.e. difference between baseline mean and follow-up mean divided by baseline standard deviation [SD]). A Z-score of 1.0 or more was used as a cut-off to identify patients with a relevant deterioration of HRQOL at follow-up.

Results

Mean age of the study cohort (n = 318) was 57 ± 17 (± SD) years, median 59; 58% were male. Mean ICU length of stay was 11 ± 19 days, median 4.5. Mean APACHE II score after 24 hours was 18 ± 10, mean TISS score was 33 ± 14. One hundred and seventy patients (53%) had MOD with a mean SOFA TMS of 11.8 ± 4. Cumulative mortality rates for non-MOD/MOD patients were 3%/45% in the ICU, 6%/57% in the hospital, and 12%/64% at 6 month follow-up. At follow-up HRQOL data could be obtained in 118 non-MOD and 53 MOD patients, 19 patients were lost to follow-up.

Compared with normative population data pre-ICU HRQOL was significantly (P < 0.0005) impaired in all ICU patients. MOD patients demonstrated more severe deteriorated pre-ICU physical health scores than non-MOD patients (P < 0.0005), whereas mental health domains did not differ between the two groups (P = 0.61). Survivors of MOD showed further deteriorated physical health scores at follow-up (P = 0.002) but unchanged mental health (P = 0.51). Non-MOD patients demonstrated unchanged or even improved scores in all eight SF-36 domains. The majority of the survivors (94%) were living at home. Ninety-one percent of those previously in employment had returned to their former work.

Conclusion

Using age and gender matched population norms MOD patients demonstrated more severe impaired pre-ICU physical health scores than non-MOD patients. At follow-up a deterioration in most areas of physical health was noted in MOD but not in non-MOD patients, whereas domains of mental health did not differ between the two groups. The SF-36 seems to have sufficient discriminative validity when used to measure HRQOL in survivors of MOD.