Heroin-dependent patient satisfaction with methadone as a medication influences satisfaction with basic interventions delivered by staff to implement methadone maintenance treatment

Figures & data

Table 1 Description of the participants

Variables	Participants (n=210)
Age (years), mean (SD)	41.66 (6.50)
Male gender (%)	75.7
Years of education, mean (SD)	10.65 (2.87)
Marital status (%)
Single	56.7
Married or living with a partner	19.5
Separated or divorced	18.6
Widowed	5.2
Heroin use
Age of onset (years), mean (SD)	20.53 (6.28)
Time of use (months), mean (SD)	137.22 (84.15)
Main route of administration (%)
Intravenous	66.0
Intranasal	17.7
Intrapulmonary	16.3
MMT
Duration lifetime (months), mean (SD)	109.21 (71.50)
Current dose (mg/d), mean (SD)	66.75 (82.53)
Current dose range (%)
<60 mg/d	62.1
60–100 mg/d	24.3
>100 mg/d	13.6
History of non-opioid substance use (%)
Alcohol	70.0
Benzodiazepines	64.3
Cannabis	87.6
Cocaine	93.3
Tobacco	97.1

Note: History of use of non-opioid substances was defined as consumption of these substances at least 20 times in a lifetime (without a prescription in the case of benzodiazepines).

Abbreviation: MMT, methadone maintenance treatment.

Table 2 SASMAT-METHER and basic interventions data distribution and item factor loadings

Item	Data distribution (%)						SASMAT-METHER ESEM factor loadings			Basic interventions factor loadings
	1	2	3	4	5	MV	F1	F2	F3
SASMAT-METHER
Impact on enjoying pleasant things of life	9.5	18.1	30.0	33.3	9.0	0.0	0.650	0.187	0.006
Tolerability regarding side effects	7.6	16.7	22.4	45.7	7.1	0.5	0.448	0.202	0.057
Impact on overall physical health	9.0	21.4	31.4	34.3	3.8	0.0	0.575	0.033	0.102
Compatibility with everyday activities	6.7	12.4	20.5	45.7	14.3	0.5	0.929	−0.053	−0.017
Compatibility with leisure activities	5.2	13.3	22.9	48.6	9.5	0.5	0.902	0.016	−0.054
Compatibility with social activities	4.3	16.7	23.8	48.1	7.1	0.0	0.841	−0.036	0.012
Compatibility with work/student activitya	7.1/4.8	9.0/4.8	19.0/17.6	38.6/14.8	11.4/5.2	14.8/52.9	0.842	−0.173	0.008
Efficacy to stop thinking about heroin	9.0	11.0	18.6	41.9	19.5	0.0	−0.010	0.863	0.026
Efficacy to avoid paying attention to everything around me related to heroin	5.2	14.3	17.1	43.8	19.5	0.0	0.026	0.778	−0.029
Efficacy in reducing heroin craving	3.8	16.7	9.5	44.8	25.2	0.0	−0.037	0.855	0.094
Efficacy in preventing heroin withdrawal	2.9	4.3	5.2	53.3	33.8	0.5	0.276	0.634	−0.048
Efficacy in reducing heroin use	2.9	6.7	10.0	52.4	28.1	0.0	0.094	0.721	0.086
Efficacy to stop thinking about other substances	14.8	25.2	33.3	21.4	4.3	1.0	0.071	0.109	0.747
Efficacy to avoid paying attention to everything around me related to other substances	9.5	24.8	33.3	27.1	4.3	1.0	0.025	0.090	0.833
Efficacy in reducing other substance craving	11.9	26.7	31.4	24.8	4.3	1.0	−0.010	0.072	0.866
Efficacy in preventing other substance withdrawal	10.0	21.4	34.3	27.1	6.2	1.0	−0.206	−0.014	0.959
Efficacy in reducing other substance use	11.4	22.4	31.9	28.6	4.8	1.0	−0.134	−0.003	0.982
Basic interventions (Verona service satisfaction scale for methadone treatment)
Helping patient deal with problems	4.3	8.6	17.1	45.7	24.3	0.0				0.779
Physicians’ ability to listen	5.2	9.5	12.9	42.4	24.8	5.2				0.870
Physicians’ manner	3.8	6.7	11.9	39.5	33.3	4.8				0.853
Referring to other specialists	5.2	8.1	29.0	40.0	17.1	0.5				0.722
Overall satisfaction	2.9	5.2	16.2	54.3	21.4	0.0				0.884
Nurses’ manner	1.4	2.4	8.6	46.7	36.2	4.8				0.645
Improving relationship between patient and relatives	6.7	8.6	50.5	21.9	12.4	0.0				0.860
Helping family members to understand patient’s problems	10.0	10.5	47.6	20.5	11.0	0.5				0.887
Nurses’ knowledge of patient’s medical history	2.9	6.2	22.4	47.1	20.5	1.0				0.741
Information on addiction	7.1	9.0	22.4	44.3	16.7	0.5				0.834
Helping patient in relationships outside the family	8.6	15.2	48.1	20.0	8.1	0.0				0.745
Instructions between visits	6.7	7.1	24.3	49.5	12.4	0.0				0.767
Helping patient to look after himself	7.1	15.2	31.9	31.4	14.3	0.0				0.815
Nurses’ ability to listen	2.4	5.2	14.3	50.0	21.0	7.1				0.717
Help received for methadone side effects	4.3	11.0	42.4	31.9	10.5	0.0				0.663

Notes: F1, personal functioning and well-being; F2, anti-addictive effect on heroin; F3, anti-addictive effect on other substances.

a F1 item 7 corresponds to the mean between items 7 and 8 of personal functioning and well-being. Data distributions of both items are presented in this table. The most selected category for each item is highlighted in bold.

Abbreviations: ESEM, exploratory structural equation model; SASMAT-METHER, scale to assess satisfaction with medications for addiction treatment – methadone for heroin addiction; MV, missing values.

Table 4 Subscale data and correlations between factors

Factor	Mean (SD)	% satisfied	1	2	3	4
SASMAT-METHER
1. Personal functioning and well-being	3.31 (0.80)	65.2	1
2. Anti-addictive effect on heroin	3.78 (0.86)	78.6	0.488	1
3. Anti-addictive effect on other substances	2.88 (0.94)	42.3	0.304	0.431	1
VSSS-MT
4. Basic interventions	3.58 (0.76)	77.1	0.299	0.286	0.265	1

Notes: % satisfied = patients with a score >3 in a particular subscale. All latent correlations were significant at p<0.001.

Abbreviations: SASMAT-METHER, scale to assess satisfaction with medications for addiction treatment – methadone for heroin addiction; VSSS-MT, Verona service satisfaction scale for methadone-treated patients.

Table 3 SASMAT-METHER measurement models comparison

Model	χ^2 (df)	p-value	RMSEA (90% CI)	CFI	TLI	Δχ^2 (Δdf)	p-value	ΔRMSEA	ΔCFI	ΔTLI
Model 1 – ESEM	200.546 (88)	<0.001	0.078 (0.064–0.092)	0.983	0.973
Model 2 – three correlated factors CFA	312.420 (116)	<0.001	0.090 (0.078–0.102)	0.970	0.964	115.675 (28)	<0.001	0.012	−0.013	−0.009
Model 3 – three uncorrelated factors CFA	934.044 (119)	<0.001	0.181 (0.170–0.191)	0.874	0.856	135.274 (3)	<0.001	0.091	−0.096	−0.108
Model 4 – one factor	1,550.953 (119)	<0.001	0.239 (0.229–0.250)	0.778	0.747	282.187 (3)	<0.001	0.149	−0.192	−0.217

Notes: The table presents the taxonomy of nested measurement models. The selected model is highlighted in bold.

Abbreviations: SASMAT-METHER, scale to assess satisfaction with medications for addiction treatment – methadone for heroin addiction; ESEM, exploratory structural equation model; CFA, confirmatory factor analysis; RMSEA, root mean square error of approximation; CI, confidence interval; CFI, comparative fit index; TLI, Tucker–Lewis index.

Figure 1 Structural model describing the influence of SASMAT-METHER factors on patient satisfaction with the basic interventions conducted at methadone treatment centers.

Notes: All coefficients are standardized. *p<0.05.
Abbreviation: SASMAT-METHER, scale to assess satisfaction with medications for addiction treatment – methadone for heroin addiction.