Trajectories of remission and mortality over 13 years after intake to substance use treatment.

Background: Little is known about the relationships between long-term patterns of substance use and mortality risk among substance use disorder (SUD) patients.

Objective: To determine distinct patterns of remission and relapse of SUD over time and examine their relationship with mortality.

Methods: The study site was Kaiser Permanente of Northern California. Data for 997 adults who entered substance use treatment between 1994 and 1996 and 4,241 non-SUD patients with similar demographic distributions (35% women in both groups) were analyzed. Latent class growth analysis identified distinct remission trajectory groups over 13 years among SUD patients, and survival analyses were conducted to examine the risk of death between remission trajectory groups, and SUD and non-SUD patients within each remission trajectory group.

Results: Three distinct remission trajectory groups were identified among SUD patients: 1) early relapse-low remission probabilities; 2) declining remission-decreasing remission probabilities; and 3) stable remission-stable remission probabilities across all time points. Among the SUD patients, the early relapse group had a higher risk of death than those stably remitted; stable and declining remission groups did not differ. Comparisons within each remission trajectory group showed that SUD patients in the early relapse and stable remission groups had higher risks of death compared with non-SUD patients; there were no differences within the declining group.

Conclusions: SUD patients in the stable remission group had lower survival rates compared with non-SUD patients. These findings underline the importance of continuously addressing healthcare needs of individuals with SUD, even in the presence of long-term remission.