Prognostic factors of inhospital death in elderly patients: a time-to-event analysis of a cohort study in Martinique (French West Indies)

OBJECTIVE: The primary objective was to identify predictive factors of inhospital death in a population of patients aged 65 years or older hospitalised with Chikungunya virus (CHIKV) infection. The secondary aim was to develop and validate a predictive score for inhospital death based on the predictors identified. DESIGN: Longitudinal retrospective study from January to December 2014. SETTING: University Hospital of Martinique. PARTICIPANTS: Patients aged ≥65 years, admitted to any clinical ward and who underwent reverse transcription PCR testing for CHIKV infection. OUTCOME: Independent predictors of inhospital death were identified using multivariable Cox regression modelling. A predictive score was created using the adjusted HRs of factors associated with inhospital death. Receiver operating characteristic curve analysis was used to determine the best cut-off value. Bootstrap analysis was used to evaluate internal validity. RESULTS: Overall, 385 patients aged ≥65 years were included (average age: 80±8 years). Half were women, and 35 (9.1%) died during the hospital stay. Seven variables were found to be independently associated with inhospital death (concurrent cardiovascular disorders: HR 11.8, 95% CI 4.5 to 30.8; concurrent respiratory infection: HR 9.6, 95% CI 3.4 to 27.2; concurrent sensorimotor deficit: HR 7.6, 95% CI 2.0 to 28.5; absence of musculoskeletal pain: HR 2.6, 95% CI 1.3 to 5.3; history of alcoholism: HR 2.5, 95% CI 1.1 to 5.9; concurrent digestive symptoms: HR 2.4, 95% CI 1.2 to 4.9; presence of confusion or delirium: HR 2.1, 95% CI 1.1 to 4.2). The score ranged from 0 to 25, with an average of 6±6. The area under the curve was excellent (0.90; 95% CI 0.86 to 0.94). The best cut-off value was a score ≥8 points, with a sensitivity of 91% (82%–100%) and specificity of 75% (70%–80%). CONCLUSIONS: Signs observed by the clinician during the initial examination could predict inhospital death. The score will be helpful for early management of elderly subjects presenting within 7 days of symptom onset in the context of CHIKV outbreaks.