Increased somatic morbidity in the first year after leaving opioid maintenance treatment: results from a Norwegian cohort study.

BACKGROUND/AIMS: Some patients on opioid maintenance treatment (OMT) leave treatment temporarily or permanently. This study investigated whether patients interrupting their OMT differed from non-interrupters in sociodemographic and drug-use characteristics and examined acute/sub-acute somatic morbidity among the interrupters, prior to, during, and after OMT.

METHODS: Cohort design. OBSERVATION PERIOD: 5 years prior to, up to first 5 years during, and up to 5 years after interruption of OMT.

PARTICIPANTS: The sample (n = 200) comprised 51 OMT interrupters and 149 non-interrupters. Data on patient characteristics were obtained from interviews and OMT register information. Data on somatic morbidity were gathered from hospital records.

MEASUREMENTS: Key patient characteristics among OMT interrupters and non-interrupters. Incidence rates of acute and sub-acute somatic disease incidents leading to hospital treatment (drug-related/non-drug-related/injuries) prior to/during/after OMT.

RESULTS: Interrupters and non-interrupters did not differ in sociodemographic characteristics, while longer duration of amphetamine and benzodiazepine dependence predicted OMT interruption. Interrupters scored significantly higher on drug-taking and overdose during OMT but still had a significant 41% reduction in drug-related treatment, episodes. After interruption of treatment, such episodes increased markedly and were 3.6 times more frequent during the first post-OMT year compared to the pre-OMT period (p < 0.001). This increase was highest during the first months after OMT interruption. 2-5 years after interruption there was no significant increase.

CONCLUSIONS: Increased somatic morbidity was found among OMT interrupters during the first year after OMT, and especially during the immediate post-treatment period.