Validation of two quality of life questionnaires suitable for intensive care patients

To validate two instruments measuring quality of life (QOL) suitable for patients admitted to the intensive care unit (ICU): QOL-IT and QOL-SP.

Prospective study using patient interviews.

Two four-bed surgical-medical ICUs in a 960-bed teaching hospital.

One hundred seventy-two adult, co-operative patients consecutively admitted to ICU for more than 24 h were interviewed. One year after hospital discharge, 84 survivors were interviewed again. Inter-observer reproducibility was investigated in 36 patients. To validate the instruments, the QOL-IT and QOL-SP scores reported by patients were considered according to the functional limitation evaluated by the interviewer. Moreover, the theoretical prediction that patients with chronic diseases should have a worse QOL before ICU admission than patients with only acute illness was tested. QOL-IT and QOL-SP scores given 1 year after hospital discharge were compared with those recorded at the first interview.

Inter-observer reproducibility was excellent. The possible range of QOL-IT is 0-20 and that of QOL-SP 0-29. According to the functional limitation (absent, mild or severe), the median QOL-IT score increased from 3 to 6 to 13 and QOL-SP from 2 to 6 to 12 (p< 0.0001). The patients with chronic diseases gave scores significantly higher than the patients with only acute illness (median QOL-IT 8 versus 3, p< 0.013; QOL-SP 8 versus 4, p< 0.004). The median QOL-IT score changed from 3 to 4 one year after hospital discharge, a difference which is statistically (p< 0.001), but not clinically, significant. The median QOL-SP score was 3 and did not change.

QOL-IT and QOL-SP are instruments able to discriminate between different health states.