Sickness Impact Profile Score versus a Modified Short-Form survey for functional outcome assessment: acceptability, reliability, and validity in critically ill patients with prolonged intensive care unit stays.

Background: Quality of life after surgical critical illness is an important measure of outcome. The Sickness Impact Profile Score (SIP) has been validated in critically ill patients, but the Modified Short-Form (MSF) has not been directly compared with it.
Methods: The SIP and MSF-36 were coadministered to 127 patients (surrogates) with a prolonged surgical critical illness at baseline at 1, 3, 6, and 12 months. Reliability, validity, and acceptability were determined for overall and subscores at each time point.
Results: The overall SIP and eight subscores, including physical health and psychosocial health, were all significantly improved at 1 year compared with baseline (p < 0.05). However, the MSF-36 was improved only in health perception (p < 0.05), but pain scores were higher (p < 0.05) than at baseline. Internal consistency of the MSF-36 was poor at 1 and 3 months. Correlation between the tools was excellent at baseline and 1 year but variable in overall and subscores at other time points.
Conclusion: The SIP is more comprehensive, reliable, and acceptable in determining specific quality-of-life abnormalities, but the MSF-36 is easier to administer and correlates well at baseline and 1 year in patients with a prolonged critical illness.