Factors associated with non-response at health-related quality of life follow-up in a septic shock trial

BACKGROUND: Follow-up of intensive care unit (ICU) patients often includes health-related quality of life (HRQoL) surveying, but non-responders hamper the interpretation. Our aim was to assess factors for non-response to HRQoL survey in ICU patients with septic shock at follow-up in a clinical trial.

METHODS: In a post hoc follow-up registry study, we assessed all the Danish survivors in the Transfusion-Requirements in Septic Shock trial patients, who were mailed the Short Form 36-item Survey (SF-36) 1-year after randomization. We used covariates from the trial database merged with covariates from nation-wide registries using the unique national identification number to explore possible factors for not responding. Five covariates were pre-specified to be included in the primary multivariate analysis: age, number of days in hospital from randomization to follow-up, level of education, cohabitation and employment status at follow-up. We compared the mortality from 1-year survival (2012-2014) till end of final follow-up (January 2016) between non-responders and responders.

RESULTS: We assessed 308 survivors of whom 108 (35%) were non-responders. In the primary analysis lower age (odds ratio 1.03, 95% CI [1.01-1.05]), more admission days in hospital (1.006 [1.001-1.011]) and living alone (4.33 [2.46-7.63]) were associated with non-responding, whereas the level of education and employment status were not. Non-responders had a hazard ratio of 1.63 [0.97-2.72] for mortality from 1-year follow-up to final follow-up as compared to the responders.

CONCLUSION: Being younger, spending more days in hospital and living alone were all associated with non-response at 1-year HRQoL follow-up among ICU patients with septic shock.