Subtypes of patients with opioid use disorder in methadone maintenance treatment: A pathways model analysis

Figures & data

Table 1. Sample characteristics (N = 118)

	n (%)	M (SD)	Range
Demographic and Clinical Factors
Black/African American Race	75 (63.6)
Male Gender	69 (58.5)
High School Education	83 (70.3)
Age at Survey		52.65 (13.63)	25–73
Age of Regular Opioid Use Onset (DHUQ)		27.11 (9.67)	14–59
Prior MMT	92 (78.0)
Lifetime Opioid-Related Consequences (HUC)		9.72 (3.90)	1–16
Injection Opioid Use in Lifetime (DHUQ)	52 (44.1)
Substance Misuse History in Social Network	84 (72.4)
Lived with Someone Misusing Substances	87 (73.7)
Positive Screen, Co-Occurring Addiction	75 (63.0)
Past-Year Cocaine (SDS)	46 (39.0)
Past-Year Alcohol (AUDIT-C)	30 (25.4)
Lifetime Gambling (NODS-CLiP)	34 (28.8)
Emotional Vulnerability
Loneliness (UCLA-3)		5.84 (2.04)	3–9
Depression (DASS-21)		13.36 (8.83)	0–40
Stress (DASS-21)		16.34 (9.14)	2–42
Physical Abuse (CTQ-SF)		9.54 (5.12)	5–25
Emotional Abuse (CTQ-SF)		10.37 (5.34)	5–25
Sexual Abuse (CTQ-SF)		7.79 (5.95)	5–25
Interpersonal Violence (CTS2)		2.93 (2.84)	0–8
Community Violence (TISH)		9.06 (3.38)	0–15
Opioid-Related Coping Motives (DMQ)		16.29 (4.11)	3–21
Antisocial Impulsivist
Trait-based Impulsivity (BIS-15)		36.58 (7.33)	16–60
Meaning-in-life Search (MLQ)		15.53 (4.30)	3–21
Meaning-in-life Presence (MLQ)		14.07 (4.78)	3–21

Note: Reference categories include Other Race, Female Gender, Less Than High School Degree, and the absence of all remaining dichotomous measures. The HUC scale excluded the three-item factor assessing school-related consequences due to the age range in this sample.

Table 2. Model fit indices

Number of Classes	AIC	BIC	ABIC	Entropy	BLRT p-value	Smallest class, %
1	8511.149	8577.645	8501.775	N/A	N/A	N/A
2	8255.922	8358.437	8241.471	.869	<.001	39.5
3	8088.346	8226.881	8068.818	.932	<.001	15.3
4	8018.594	8193.147	7993.989	.951	<.001	5.9
5	7991.747	8202.319	7962.064	.941	<.001	3.4

Note. AIC = Akaike Information Criterion; BIC = Bayesian Information Criterion; ABIC = Adjusted Bayesian Information Criterion; BLRT = Bootstrap Likelihood Ratio Test. Models 4 and 5 did not converge.

Table 3. Three-latent-class model of the Pathways Model indicators in patients initiating methadone maintenance treatment for opioid use disorder

	Class 1: Opioid-Related Only (55.9%)	Class 2: Personal Trauma/ Emotionally Vulnerable (15.3%)	Class 3: Impulsive/Current Psychopathology (28.8%)
Indicators	Mean (95% CI)	Mean (95% CI)	Mean (95% CI)
Emotional Vulnerablility
Loneliness	4.88 (4.24, 5.42)	6.02 (2.21, 6.87)	7.55 (6.97, 8.13)^c, d
Depression	8.86 (7.39, 10.32)	15.18 (11.23, 19.88)^a	20.82 (16.77, 24.87)^c
Stress	11.22 (9.42, 13.02)	20.28 (16.28, 25.06)^a	23.87 (20.60, 27.15)^c
Physical Abuse	7.15 (6.46, 7.84)	14.93 (12.53, 17.78)^a	11.26 (9.03, 13.49)^c
Emotional Abuse	7.22 (6.19, 8.24)	14.50 (12.36, 17.05)^a	14.16 (11.88, 16.44)^c
Sexual Abuse	5.04 (4.95, 5.13)	20.95 (18.87, 23.43)^a, b	6.18 (5.43, 7.08)^c
Interpersonal Violence	1.58 (1.02, 2.14)	5.95 (5.02, 7.06)^a, b	3.91 (2.82, 5.00)^c
Community Violence	7.69 (6.89, 8.49)	10.60 (9.57, 11.82)^a	10.84 (9.62, 12.06)^c
Opioid-Related Coping Motives	14.43 (13.26, 15.61)	18.46 (17.40, 19.73)^a	18.64 (17.80, 19.48)^c
Antisocial Impulsivist
Trait-based Impulsivity	33.43 (31.68, 35.17)	39.62 (36.79, 43.00)^a	40.90 (38.62, 43.18)^c
Meaning-in-life Search	15.29 (14.19, 16.39)	17.12 (15.52, 19.02)	15.19 (13.68, 16.69)
Meaning-in-life Presence*	14.90 (13.82, 15.98)	14.93 (12.83, 17.44)	12.07 (10.05, 14.10)

Note. CI = Confidence Interval. All indicators are continuous. *Higher scores for Meaning-in-Life Presence is a protective measure for OUD risk. Superscripts indicate confidence bands that do not overlap, for the following group comparisons: ^a Class 2 higher than Class 1; ^b Class 2 higher than Class 3; ^c Class 3 higher than Class 1; ^d Class 3 higher than Class 2.

Figure 1. Plot of the three-latent-class model of the pathways model indicators in patients receiving methadone maintenance treatment for OUD.

*Higher scores for meaning-in-life presence is a protective measure for OUD risk. Score range in sample in parentheses.

Table 4. Multinomial logistic regression results predicting latent class membership

	Class 1 vs.					Class 2 vs.
	Class 2		Class 3			Class 3
Reference Group	OR	95% CI	OR	95% CI		OR	95% CI
Black/African American Race	0.75	0.11–5.04	3.72	0.21–65.83		4.95	0.41–60.33
Male Gender	0.14*	0.03–0.76	0.49	0.15–1.66		3.47	0.63–19.09
High School Education	0.60	0.12–2.94	0.90	0.20–4.10		1.50	0.35–6.45
Age at Survey	0.91*	0.84–0.99	0.90	0.81–1.01		0.99	0.91–1.09
Age of Regular Opioid Use Onset	1.03	0.94–1.13	1.00	0.94–1.05		0.96	0.88–1.06
Prior MMT	1.30	0.23–7.23	0.49	0.09–2.62		0.38	0.07–1.90
Lifetime Opioid-Related Consequences	1.26*	1.01–1.58	1.30*	1.09–1.55		1.03	0.85–1.25
Injection Opioid Use in Lifetime	0.41	0.06–2.70	0.43	0.12–1.51		1.05	0.19–5.84
Substance Misuse History in Social Network	12.25*	1.63–91.98	2.48	0.47–13.14		0.20	0.02–1.73
Lived with Someone Misusing Substances	0.30	0.07–1.40	0.44	0.09–2.22		1.45	0.34–6.18
Positive Screen, Co-Occurring Addiction	1.13	0.28–4.58	4.08	0.73–22.88		3.62	0.86–15.28

Note. OR = Odds Ratio; CI = Confidence Interval. Positive screens for addiction was defined as having one or more positive screen on co-occurring addiction measures for alcohol, cocaine, and gambling.

* denotes that confidence interval does not contain 1.