Predictors of problematic substance use 18 years after treatment: a longitudinal cohort study of persons with substance use disorders

Figures & data

Figure 1. Flow diagram; participants, data collection and analyzed data during the study.

Table 1. Characteristics of participants, nonparticipants and deceased in the follow-up 18 years after treatment

		Participants (n = 91)	Nonparticipants (n = 103)	p^a	Deceased (n = 93)	p^b
Gender (male)	n (%)	64 (70)	69 (67)	0.617^c	74 (80)	0.148^c
Age, years at baseline	mean (SD)	36.5 (10.1)	34.7 (10.8)	0.218^d	44.2 (11.1)	<0.001^d
Onset SUD before age 18 years	n (%)	50 (55)	46 (45)	0.153^c	35 (38)	0.019^c
Duration since first SUD, years at baseline	mean (SD)	13.5 (8.3)	11.7 (8.0)	0.111^d	16.2 (9.6)	0.047
Only AUD (vs.other SUDs) baseline	n (%)	36 (40)	34 (33)	0.343^c	60 (65)	0.001^c
Lifetime affective disorders baseline	n (%)	63 (72)	69 (68)	0.556^c	47 (51)	0.004^c
Lifetime anxiety disorders baseline	n (%)	74 (82)	83 (84)	0.767^c	72 (80)	0.703^c
Number of personality disorders baseline	mean (SD)	2.8 (2.5)	2.7 (2.8)	0.595^d	2.7 (2.8)	0.407^d
HSCL-25 baseline	mean (SD)	2.14 (0.57)	2.02 (0.63)	0.134^d	1.97 (0.54)	0.060^d
Inpatient treatment at baseline	n (%)	44 (48)	59 (57)	0.214^c	63 (68)	0.008^d

^aComparison between participants and nonparticipants

^bComparison between participants and deceased

^c χ2-test

^dMann-Whitney U test

SUD = Substance Use Disorder

AUD = Alcohol Use Disorder

HSCL-25 = Hopkins Symptom Check List 25

SD = Standard Deviation

Table 2. Comparison between participants with no current problematic substance use and current problematic substance use 18 years after treatment.*

		No current problematic substance use (n = 39)	Current problematic substance use (n = 36)	p
Demographics
Gender, male	n (%)	27 (69)	28 (78)	0.403^a
Age, years at the 18-year follow-up study	mean (SD)	56.5(10.9)	53.6(8.6)	0.212^c
Married or cohabitant at baseline	n (%)	13 (34)	16 (44)	0.367^a
Completed upper secondary school at baseline	n (%)	19 (51)	18 (50)	0.908^a
Full-time ordinary work at baseline	n (%)	8 (21)	9 (25)	0.687^a
Mental health
Diagnoses CIDI nonhierarchical lifetime at baseline
Affective disorder	n (%)	29 (76)	26 (74)	0.841^a
Anxiety disorder	n (%)	31 (80)	38 (89)	0.290^a
Number of mental disorders (minus SUD and personality disorders)	mean (SD)	3.67 (2.68)	3.75 (2.35)	0.668^b
Personality disorders MCMI-II at baseline
Number of personality disorders	mean (SD)	2.28 (2.43)	3.69 (2.51)	0.013^b
Mental distress
HSCL-25 at baseline	mean (SD)	1.98 (0.49)	2.34 (0.59)	0.006^c
Substance use
Number of SUDs at baseline	mean (SD)	2.46 (1.83)	2.72(2.15)	0.827^b
Age onset SUD	mean (SD)	22.5 (9.7)	19.3 (8.5)	0.035^b
Only AUD (vs. other SUDs) at baseline	n (%)	17 (44)	16 (44)	0.941^a

*Participants with complete data collection at baseline and the 18-year follow-up study (n = 75)

^aχ2-test.

^bMann-Whitney U test.

^cIndependent samples t-test.

CIDI = Composite International Diagnostic Interview

SUD = Substance Use Disorder

MCMI-II = The Millon Clinical Multiaxial Inventory II

HSCL-25 = Hopkins Symptom Check List 25

AUD = Alcohol Use Disorder

SD = Standard Deviation

Table 3. Bivariate and multivariate logistic regression analysis of having current problematic substance use 18 years after treatment

		Logistic regression model (n = 75)
		Bivariate^a			Multivariate^b,c
	n (%)/mean (SD)	OR	95% CI	p	OR	95% CI	p
Demographics
Gender (male)	55 (73)	0.64	0.23–1.82	0.405	0.69	0.21–2.24	0.536
Age	55.1 (9.9)	0.97	0.93–1.02	0.210	0.98	0.92–1.05	0.629
Mental health at baseline
Number of personality disorders	3.0 (2.5)	1.26	1.04–1.53	0.019	1.09	0.86 − 1.38	0.479
HSCL-25 mean score	2.15 (0.57)	3.40	1.37–8.49	0.009	3.24	1.08–9.68	0.035
Substance use at baseline
Age onset SUD	21.0 (9.2)	0.96	0.91–1.01	0.142	0.96	0.90–1.04	0.335

^aBivariate unadjusted analysis for having current problematic substance use at the 18-year follow-up study

^bMultivariate adjusted analysis for having current problematic substance use at the 18-year follow-up study, with all covariates that reached p < 0.2, plus gender and age, in the bivariate analysis.

^cNagelkerke`s R² for the multivariate analysis was 0.210 and the Hosmer-Lemeshow goodness of fit test was χ2- = 3.134, df = 7, p = 0.872.

HSCL-25 = Hopkins Symptom Check List 25

SUD = Substance Use Disorder

SD = Standard Deviation

OR = Odds Ratio

CI = Confidence Interval