The association between age of onset of opioid use and comorbidity among opioid dependent patients receiving methadone maintenance therapy

Table 1 Baseline participant characteristics (total N = 627)

	Mean (SD)	Median (IQR)
Participant characteristic
Current age (years)	38.8 (11.1)	37.0 (19.0)
Methadone dose (mg/day)	77.24 (46.10)	70.00 (55.00)
Age of onset of opioid use (years)	25.6 (8.8)	24.0 (13.0)
BMI (kg/m²)	27.92 (8.88)	26.03 (7.76)

	Percentage of total (N)
Female	45.1 (283)
Current smoking	84.5 (530)
Participants with ≥1 comorbidity	86.3 (541)
Participants with physical comorbidity^a	68.3 (428)
Participants with psychiatric comorbidity^b	57.7 (362)
Age of onset of opioid use categories
17 years and younger	19.0 (119)
18–25 years	38.9 (244)
26–30 years	15.5 (97)
31 years and older	26.6 (167)

^aThe physical comorbidities comprising the composite outcome included chronic pain (n = 252), epilepsy (n = 16), hepatitis (n = 141), liver disease (n = 31), HIV (n = 3), pulmonary disorders such as asthma and chronic obstructive pulmonary disorder (n = 52), diabetes mellitus type I or type II (n = 33), cardiovascular history including hypertension or cardiomyopathy (n = 33), arthritis (n = 25), inflammatory bowel disease (n = 6), endocrine disorders including hypothyroidism and hyperthyroidism (n = 15), cancer (n = 6), renal disorders (n = 5), neurological disorders including neuropathies and multiple sclerosis (n = 20), endometriosis (n = 7), dermatological disorders including eczema and psoriasis (n = 2), inactive TB (n = 2), and syphilis (n = 1)
^bThe psychiatric comorbidities comprising the composite outcome included mood disorders such as depression and mania (n = 87), anxiety disorders such as generalized anxiety and obsessive compulsive disorder (n = 212), substance use disorders other than opioids (n = 83), psychotic disorders (n = 24), eating disorders (n = 4), antisocial personality disorder (n = 144)

ISSN: 1940-0640