Longitudinal Effects of Medical Comorbidities on Functional Outcome and Life Satisfaction After Traumatic Brain Injury: An Individual Growth Curve Analysis of NIDILRR Traumatic Brain Injury Model System Data.

Only people who survived to the 10-year follow-up were included, so the paper says nothing about trajectories in people who died earlier. Follow-up was only at 1, 2, 5, and 10 years, so changes between those points could be missed. The study was observational, so it cannot show that a comorbidity caused worse function or lower life satisfaction. The paper did not evaluate whether the statistically significant differences were clinically important. Comorbidity severity and treatment were not assessed, so the study cannot say how well controlled a condition was. Medical and mental health conditions were based on self-report or proxy report about a doctor's diagnosis, not medical records. FIM data were available for 404 participants, but life-satisfaction data were available for 326 participants, so the two outcomes were not based on the same number of people. The sample was limited to people who received inpatient rehabilitation through the TBIMS, so findings may not apply to milder TBI or people who did not get inpatient rehabilitation. The work was exploratory and significance levels were not adjusted for testing many conditions, so some findings may be chance. Telephone follow-up and possible cognitive impairment may have affected the reliability of reported information.

No author conflicts of interest are stated in the supplied text. The article metadata lists research support from NIH and U.S. government funding.

Do not read these associations as proof that treating a comorbidity will improve TBI outcomes. The study did not randomise treatment, did not assess comorbidity severity or management, did not adjust for multiple comparisons, and only followed people who survived to 10 years.