Opioid maintenance treatment: trajectories in and out of treatment

Abstract

Problem: Although efficacy studies of opioid maintenance treatment (OMT) have shown evidence of treatment benefits, there is still need for studies on its effectiveness in natural clinical processes. This study investigates the development in health, substance use and social conditions of those who applied for OMT, including those denied access or discharged.

Method: First, persons assessed for admittance in 2005–2011 (n = 127) were categorized into four trajectory groups based on whether they were admitted or denied (n = 19), discharged (n = 31), readmitted (n = 21) or had been undergoing OMT without interruption (n = 56). Second, 99 of these, the analytical sample, were interviewed at follow-up using (a) the Addiction Severity Index (ASI) for seven problem-areas and housing, and (b) self-rated change in 11 problem areas. The ASI was compared to baseline interviews after 55 months (mean). Third, outcomes within groups was studied in relation to alternative interventions.

Results: Within the analytical sample, those denied OMT showed no improvements at group level, those discharged had some improvements, more if readmitted than if not and those with uninterrupted OMT showed the most comprehensive improvements. Those outside OMT, denied and discharged, had considerable mortality risks related to ongoing drug use, especially in lack of well-planned alternative interventions.

Conclusion: Improvements strongly relate to access to OMT. This study underscores that access to OMT improves the situation in all areas investigated and decreases the risk for drug-related death. It underscores the importance of two major risk situations, i.e. being denied OMT and being discharged.

Keywords:

• Opioid maintenance treatment
• drop-outs
• treatment outcome
• treatment process

Background

Opioids have documented euphoric and analgesic properties [1,2]. They can be prescribed, e.g. as painkillers, but also used for getting high and other reasons without prescription, i.e. misuse. They are known for their addictive potential, leading to disadvantaged life, health problems and premature death. In 2015, UN estimated that 53 million persons used opioids, being the major drugs causing health problems [3]. In Sweden, opioids are involved in 93 percent of drug-related mortality, with over 500 deaths in 2016 [4].

The World Health Organization defined opioid dependence (OD) as a serious chronic brain related disease [5] and recommended opioid maintenance treatment (OMT) for those suffering [6]. Evidence of its efficacy has been demonstrated [6–9] with reduced opioid use [10], decreased risk behaviors e.g. injecting drugs and criminal activities [6,11], reduced risk for infectious diseases [8,12], improved health [13], and decreased risk of fatal overdoses [8,14,15]. Successful OMT therefore generates less economic burden on society, including reduced costs for health care, social welfare, and legal services [6].

Although retention in treatment is important, OMT may be interrupted for different reasons. Some patients choose leaving OMT because it disturbs their work and family life or is perceived as controlling. But as reported in many studies, most treatment breaks are involuntary discharges based on a staff decision, due to noncompliance with clinical rules, e.g. absence from treatment for several days, or use of illicit or non-accepted drugs [16–19]. Inadequate doses prescribed in OMT, resulting in the patient having subjective withdrawal symptoms, relate to more non-accepted drug use beside OMT-medication [20]. Success in remaining drug-free after interrupted OMT is possible but not the most common outcome, partly due to problematic withdrawal symptoms also from OMT-pharmaceuticals and because of continued craving for opioids [21–23]. Such patients’ risks of mortality and returning to severe drug misuse are elevated [15,24,25]. A Swedish study on involuntary discharges show impaired living conditions concerning physical and mental health and family relations associated with their return to a drug-centred lifestyle [26].

Since 1965, OMT is practised in Sweden, as one of the first countries outside the US. It is performed under strict rules in the Codes of Statues defined by the National Board of Health and Welfare [27]. OMT is delivered in dependency clinics, and in cooperation with the municipal welfare authorities that can provide various forms of social welfare support.

In 2010, new criteria for inclusion in OMT were introduced due to new Codes of Statues, accepting only those with documented dependency on heroin, morphine or opium (HMO) while rejecting all other opioid dependents [28]. In 2011, a naturalistic study was initiated to follow a population assessed for OMT, including those admitted as well as those denied participation in OMT. Previous studies on the baseline data of that population compared those who met the HMO criteria to those with problems related to other opioids, showing that the groups are similar in diagnostic terms [29] as well as in related problems [30]. The studies found no reasons for treating the groups differently. A case study [31] shows that many clinicians developed strategies to base their admittance decisions on professional judgement and avoided applying the narrow criteria of 2010. Since the statutes were not effectively applied, the HMO categorization became less relevant for the longitudinal study. In 2016, these statutes were again changed, and those severely dependent on opioids, irrespective of type, can be admitted for OMT [32].

There is still a need to follow the process of all those seeking OMT in terms of whether they were admitted or not, whether treatment disruptions occurred or not, and how these relate to their development. Quality in treatment should benefit from better knowledge of trajectory subgroups’ processes.

Focus and aim

The present study focuses on persons assessed for OMT. The aim is to follow estimated changes in health, substance use and social conditions from the time they applied for OMT until follow-up interviews, and compare that development between trajectory groups, based on whether they were admitted or denied, discharged, or readmitted.

Material and methods

This is a longitudinal naturalistic study conducted at a Swedish county hospital in Jönköping region with about 350,000 inhabitants. Patients in OMT during 2005–2011, or persons who then applied for admittance, were followed from T1 to T2, where T1 is the time of OMT assessment (baseline), and T2 is the time of follow-up. The observed time duration varied from 1 to 141 months, with a mean of 55.2 (s.d. = 26.7) months.

Study population

The study population consists of 127 persons in, or considered for, OMT and assessed according to clinical routines. Of these, 16 percent were women and mean age at baseline was 36.1 (s.d. = 10.2) years. They had extensive problems and more than five previous addiction treatments [30]. Eighty-four per cent injected drugs. More than 90 per cent used multiple substances and had experienced multiple overdoses.

Twenty-eight people were lost to follow-up for the following reasons: 11 had died, 10 declined participation, five could not be found or did not respond to the invitation to be interviewed, and two persons were unable to participate due to mental illness. Thus, 99 individuals participated in follow-up interviews (78 per cent of the original population).

Data collected

Clinical data on treatment process, i.e. when discharged and readmitted, were provided from the patient medical records. In the case of transfer to another OMT programme, such data were required from that clinic.

Contact addresses concerning those not currently in the OMT programme were acquired from the population registry.

Mortality data were acquired from the National Board of Forensic Medicine.

Follow-up interviews were conducted in 2012–2014 by the first author (BM).

The interviews took between 120 and 210 minutes to perform, with sixteen interviews on repeated occasions. While parts of the comprehensive interview have been reported in other studies [29,30], the parts used for this study are presented here.

ASI (Addiction Severity Index) was used both at T1 and T2. ASI is a globally used and valid structured interview that provides self-ratings of problem severity in seven areas—medical status, employment and support, alcohol, drugs, legal status, family and social relationships, and psychiatric health [33]. Ratings range from 0 (= no problem, no help needed) to 4 (= severe problems, assistance is definitely needed).

Within OMT assessment routines, ASI interviews are conducted (T1) by the referring municipal social counselors, who also provide plans for psychosocial interventions to supplement the medical treatment. The results of these baseline interviews were previously reported [30]. At T2, the ASI follow-up interviews were conducted by BM (author).

Some critical remarks on ASI should be mentioned. The area ‘employment and support’ implies that employment and private economy are assessed as one combined problem, although the rating question deals only with employment status. The area ‘legal status’ focuses on problems with the justice system rather than on engagement in criminal activities. The severity rating of drug problems does not separate opioids from other drugs. Given the nature of this study, there is a need to rate these separately. Therefore, we chose to combine the ASI interviews with retrospective ratings of change, in which employment, economy, criminal activities, and problems with illegal opioids and/or with other drugs are rated separately.

ASI provides information on housing that could be sorted according to housing stability and legal security of tenure. A four-point rank order scale on housing stability was constructed, with own apartment/contract as most stable [4], a welfare contract via the social welfare authorities [3], lodging with family/friends [2], and institutional living without the right to a key (custody/prison or treatment institution) or being roofless [1] as least stable.

Retrospective self-report rating of change is a simple measurement created for this study. The interviewees estimated the change since the time of assessment (T1) until follow-up (T2) in eleven areas: medical, employment, economy, alcohol use, use of opioids (illegal/non-prescribed), use of other drugs (illegal/non-prescribed), criminal activity, relations to family, relations to others, psychiatric status and housing stability. Change was marked as Much worse (−2), Worse (−1), No change (0), Better (+1) and Much better (+2).

Therefore, change was measured both prospectively, as the difference between the ASI interviews from T1 to T2 in seven problem areas plus housing, and retrospectively, from self-reports in eleven problem areas.

Change within groups were tested using Svensson’s method for analysis of differences between paired ordinal categorical data [34]. This method is recommended also for analyzing small samples [35], e.g. those denied to OMT. Using Svensson’s method, we estimated the Relative Position (RP) with standard error (S.E.) and 95 per cent confidence interval (95% CI). RP is the systematic change from T1 to T2 within groups and can vary between all being worse (−1) to all being improved (+1). We interpret RPs <0.2 (both directions ±) as modest, also when statistically significant, RPs >0.7 as strong, and those between as moderate. Differences in change between groups were analyzed comparing RP of each group to the 95% CIs of the other groups.

When frequencies in categorical variable (gender) were compared between groups, significance were tested using Chi-2, and ANOVA when means (e.g. time variables) were compared. Statistical analysis was performed in SPSS, except for Svensson´s method which was conducted in Excel [36]. The conventional five per cent level of significance was applied.

Ethics

Participation in follow-up interview was voluntary and based on informed consent. The study was subjected to ethical review and approved by the Regional Ethical Review Board in Linköping, (2011/214-31; 2013/497-32).

Results

Nineteen of the 127 were denied admittance for OMT for the following reasons: 16 since OD according to ICD-10 (F11.2) was not confirmed. Of those three with confirmed F11.2 diagnosis, two with less severe dependency were referred to and accepted psychosocial addiction treatment, and one who was too mentally ill was referred to psychiatric care. None in this population was denied OMT only for having misused the ‘wrong type’ of opioid, i.e. not HMO.

Thus, 108 patients were admitted. For nearly half of these (n = 52), OMT was interrupted for various reasons. Six were discharged on their own request. In another case, a collaborative decision was taken, and the person was transferred to the pain clinic. All others (n = 45) were discharged on staff decision for various reasons: most (n = 38) due to use of non-prescribed drugs (implying a medical risk to continuing prescribing methadone or buprenorphine), absence from OMT more than seven days (n = 4), going to prison (n = 2), and violent behavior at the clinic (n = 1).

Of 52 discharged cases, 21 were later readmitted after a renewed application, supplemented with a new care plan, including necessary complementary interventions presented by the municipal social workers.

Four trajectory groups

From three events—admitted or denied, discharged, and readmitted—we have three cut-points to divide the study population into four process trajectory groups: (1) Those Denied admittance (n = 19); (2) Those admitted, then Discharged and not readmitted (n = 31); Those admitted, then discharged, and later Readmitted (n = 21); and Those admitted who then continuously Remained until follow-up (n = 56). There were no significant differences between the trajectory groups as to age, gender or previous treatments.

Participation or not in follow-up interviews

Not all 127 in the study population could be interviewed for follow-up. In 28 cases, interviews were not conducted. The reasons are presented in Table 1.

Table 1. Attrition and participation in follow-up interviews of all assessed for OMT, distributed on process trajectories, in number of persons.

	Total (n = 127)	Denied (n = 19)	Discharged (n = 31)	Readmitted (n = 21)	Remained (n = 56)
Drug-related deaths (a)	6	3	3	0	0
Deaths not related to ongoing misuse (b)	5	0	0	0	5
Could not be interviewed due to mental status	2	1	1	0	0
Declined when asked to participate	10	5	3	0	2
Not found or did not answer invitation to be interviewed	5	1	1	0	3
Interviewed at T2	99	9	23	21	46

^aDeath related to drug intake, for example overdoses, accidents, non-prescribed drugs found at autopsy.

^bi.e. either not drug-related, or related to harm from previous drug use.

Some reasons why follow-up interviews could not be conducted indicate a harmful development related to substance use. The most obvious is death related to ongoing substance misuse. Other mortality causes may not necessarily indicate ongoing drug misuse. Death unrelated to drug misuse and death because of injuries incurred during previous active misuse, may occur despite non-misuse for many years. The persons mentally unfit for follow-up also had strong indications of problematic substance use development.

At time of follow-up, 99 persons were interviewed. In Table 2, age at T1 and T2, gender, follow-up time and time in OMT are presented, all compared between the four trajectory groups.

Table 2. Comparison of gender, age, follow-up time, and time in OMT since T1, for those interviewed (n = 99), compared between trajectory groups.

	Total (n = 99)	Denied (n = 9)	Discharged (n = 23)	Readmitted (n = 21)	Remained (n = 46)	Significance of difference, p
Gender, female %	16	11	17	10	20	0.736(a)
Age at T1, m(sd)	35.4(9.8)	30.9(10.0)	33.7(10.3)	33.5(6.8)	38.0(10.3)	0.088(b)
Age at T2, m(sd)	39.3(9.8)	34.5(10.5)	38.6(10.2)	37.4(6.7)	41.4(9.8)	0.152(b)
F-U time, months, m(sd)	55.2(6.7)	47.3(13.4)	65.3(30.1)	58.4(26.1)	50.3(26.5)	0.151(b)
OMT months since T1, m(sd)	48.9(33.7)	0.0(0.0)	35.6(27.7)	69.2(42.9)	66.2(27.5)	0.002(b)*
Previous treatments:
Alcohol-related m(sd)	3.9(11.1)	6.1(16.6)	1.1(3.0)	8.7(19.4)	2.7(1.4)	0.105(b)
Drug-related, m(sd)	9.6(10.3)	8.0(12.7)	8.3(8.6)	14.4(12.7)	8.4(9.0)	0.141(b)

Significance tested by: (a) Chi-2 test, (b) ANOVA. *Significance: Denied < Discharged < Readmitted & Remained.

The only significant difference between groups was the expected lack of duration of OMT treatment in those denied. There were no differences in mean age, gender or follow-up time, and all four groups had similar extensive attempts to treat substance-related problems before applying for OMT.

Prospective ratings of change

Baseline ratings (T1) of the seven ASI areas was published previously [30] and interested readers are referred to those. Table 3 presents changes in prospective ASI measures. Changes within groups are presented using RPs with 95% CIs. Changes between groups are analysed by comparing RPs´ 95% CIs.

Table 3. Comparison of changes (T1–T2) in four trajectory groups, concerning self-assessed ASI severity ratings of problems in seven problem areas and stability in housing.

Trajectory groups	Denied (n = 9)		Discharged (n = 23)		Readmitted (n = 21)		Remained (n = 46)		Between groups
Change in…	RP (SE)	95 % CI	RP (SE)	95 % CI	RP (SE)	95 % CI	RP (SE)	95 % CI	Based on RP 95% CI
Medical status	0.16 (0.23)	–0.28; 0.61	0.12 (0.15)	–0.18; 0.42	–0.09 (0.15)	–0.38; 0.20	0.22 (0.12)	–0.04; 0.45	G3 < G4
Employment/support	–0.10 (0.25)	–0.59; 0.39	–0.09 (0.13)	–0.34; 0.16	0.08 (0.13)	–0.18; 0.34	0.04 (0.10)	–0.16; 0.23
Alcohol	0.16 (0.21)	–0.26; 0.58	0.08 (0.12)	–0.15; 0.32	0.26 (0.11)	0.04; 0.47	0.08 (0.05)	–0.02; 0.18
Drugs	0.41(0.24)	–0.06; 0.88	0.39 (0.14)	0.11; 0.67	1.00 (0.00)	1.00; 1.00	1.00 (0.00)	1.00; 1.00	G1&G2 < G3&G4
Legal status	–0.14 (0.26)	–0.65: 0.38	–0.13 (0.15)	–0.42; 0.17	0.37 (0.13)	0.11; 0.62	0.36 (0.09)	0.20; 0.52	G1&G2 < G3&G4
Family/social relations	0.09 (0.16)	–0.23; 0.40	–0.31 (0.16)	–0.62; 0.02	0.15 (0.19)	–0.23; 0.53	0.18 (0.09)	0.04; 0.36	G2 < G1&G3&G4
Psychiatric status	–0.04 (0.23)	–0.48; 0.41	0.01 (0.11)	–0.21; 0.24	0.28 (0.14)	0.02; 0.55	0.30 (0.11)	0.09; 0.51	G1&G2 < G3&G4
Stability in housing	0.06 (0.17)	–0.28; 0.40	0.09 (0.13)	–0.16; 0.34	0.12 (0.12)	–0.12; 0.36	0.17 (0.08)	0.05; 0.34

(a) Tested by Svensson’s method.

Reported as Relative Position (RP) with standard error (SE) and 95% confidence interval (a).

Within-group changes are presented for the trajectory groups, one-by-one. Concerning those denied, no significant improvements in any examined areas were found. Although some improved, others had worse problems, resulting in no significant change on group level since all RPs have 95% CIs overlapping zero.

Among those discharged, there was a moderate change only concerning drug use although significant, since the 95% CI did not overlap zero.

Those readmitted showed significant improvements in four problem areas: drugs, legal status, alcohol and psychiatric status. A strong positive change concerned drugs, while the other changes were moderate.

Among those who remained in OMT, we found the most profound improvements in drugs, legal status, psychiatric status, family relations as well as housing. The change in drug problems was strong, while changes in legal and psychiatric status were moderate, and changes in family/social relations and housing stability were modest, yet statistically significant.

The last column shows change differences between groups concerning drugs, legal status, family/social relations and psychiatric status, with more improvements in the two groups currently in OMT, i.e. those readmitted and those remained. There was a difference in medical improvement between the two groups in OMT with more improvement in those who continuously remained than in those readmitted. Those denied and those discharged were on equally low levels of change, except for in family relations where those discharged had worse (negative RP).

Retrospective self-report ratings of change

The interviewees’ retrospective change ratings of change in 11 areas are presented in Table 4.

Table 4. Retrospective self-ratings of change in 11 areas in four trajectory groups. Reported as Relative Position (RP) with standard error (SE) and 95% confidence interval (a).

Trajectory groups	Denied (n = 9)		Discharged (n = 23)		Readmitted (n = 21)		Remained (n = 46)		Between groups
Change in …	RP (SE)	95 % CI	RP (SE)	95 % CI	RP (SE)	95 % CI	RP (SE)	95 % CI	Based on RP, 95% CI
Medical status	0.11(0.28)	–0.43; 0.65	0.48 (0.15)	0.19; 0.76	0.76 (0.11)	0.54; 0.98	0.80 (0.08)	0.65; 0.96	G1 < G2 < G3&G4
Employment status	0.22 (0.20)	–0.16; 0.61	0.43 (0.12)	0.20; 0.67	0.52 (0.14)	0.25; 0.80	0.72 (0.07)	0.59; 0.85	G1 < G3&G4 G2&G3 < G4
Personal economy	0.11(0.23)	–0.34; 0.57	0.56 (0.12)	0.33; 0.80	0.38 (0.17)	0.05; 0.71	0.74 (0.09)	0.57; 0.91	G1 < G2&G4 G2&G3 < G4
Alcohol use	0.11 (0.28)	–0.43; 0.65	0.39 (0.12)	0.16; 0.62	0.48 (0.13)	0.23; 0.72	0.59 (0.08)	0.43; 0.74	G1 < G2&G3&G4 G2 < G4
Opioid use, illegal	–0.11 (0.32)	–0.72; 0.50	0.96 (0.04)	0.88; 1.00	1.00 (0.00)	1.00; 1.00	1.00 (0.00)	1.00; 1.00	G1 < G2 < G3&G4
Other drugs, illegal	–0.11 (0.31)	–0.72; 0.50	0.87 (0.09)	0.69; 1.00	1.00 (0.00)	1.00; 1.00	0.93 (0.04)	0.86; 1.00	G1 < G2&G3&G4 G2 < G3
Criminal activities	0.33(0.30)	–0.25; 0.91	0.74 (0.09)	0.56; 0.91	0.81 (0.08)	0.65; 0.97	0.74 (0.06)	0.61; 0.86	G1 < G2&G3&G4
Relation with family	–0.33 (0.21)	–0.74; 0.08	0.37 (0.09)	0.20; 0.54	0.67 (0.12)	0.43; 0.90	0.78 (0.07)	0.65; 0.91	G1 < G2 < G3&G4
Relation with others	0.22 (0.29)	–0.34; 0.79	0.33 (0.13)	0.09; 0.58	0.71(0.13)	0.45; 0.98	0.65 (0.09)	0.48; 0.82	G1&G2 < G3&G4
Psychiatric status	0.00 (0.30)	–0.58; 0.58	0.48 (0.15)	0.19; 0.76	0.90 (0.09)	0.73; 1.00	0.94 (0.04)	0.86; 1.00	G1 < G2 < G3&G4
Stability in housing	0.11 (0.23)	–0.35; 0.57	0.39 (0.12)	0.16; 0.62	0.76 (0.11)	0.16; 0.62	0.83 (0.06)	0.72; 0.93	G1 < G2 < G3&G4

(a) Tested by Svensson’s method.

First, within group differences were analyzed. In those denied, the self-rated retrospective change was insignificant in all 11 areas.

In those discharged, there were significant changes (95% CI not overlapping zero) for all 11 areas. Strong RPs were found concerning illegal opioid use, other drug use and criminal activities, while for all other areas, RPs were moderate.

For those readmitted, significant changes were found in all areas. Here, strong changes were found in seven areas (opioid use, other drugs, psychiatric status, criminal activities, housing, and relations with others), while changes in other areas were moderate.

For those continuously in OMT, there were significant improvements in all 11 areas and strong in all but two areas, while moderate on the remaining two (relations with others and alcohol use).

Comparing RPs and 95% CIs indicated significant between group differences in all areas, although with somewhat different patterns. Those denied OMT seem however to be the lowest in all areas, equal to those discharged only in relations to others. Those discharged have lower changes compared to both groups in OMT concerning medical health, psychiatric health, opioid use, family relations, relations to others, and housing stability. In employment, personal economy, and alcohol use, those discharged improved less than those remained, and concerning other illegal drugs, they improved less than those readmitted. Differences between the two groups in OMT are few. Those who remained in treatment have more improvements than those readmitted in employment and personal economy.

Additional information

Some data on individual level concerning the two more problematic trajectories are relevant to this study. There were individual success stories also among those denied OMT. Two were referred to inpatient non-medical psychosocial treatment and stayed drug-free after that. Of those lacking an F11.2 diagnosis, one already had an ongoing opioid-treatment for pain-related problems and still had that at T2, while another was transferred to opioid-assisted treatment at the pain clinic.

Six persons were discharged from OMT on their own request or following a collaborative decision. Five of them had supported care after OMT, and one recovered without treatment. Of those with supported care, one was transferred to an opioid-assisted treatment at a pain unit, with no misuse at T2. The other four failed ‘drug free’ treatment: one was later readmitted for OMT, with no misuse at T2, while the remaining three were found to have severe drug problems at follow-up.

Among those eighteen discharged following a staff decision, one had recovered without treatment, two recovered after successful psychosocial residential ‘drug free’ treatment, three had an ongoing addiction treatment as inpatients and four were in jail or custody. The other eight had severe current drug problems. Therefore, among all discharged and not readmitted, most improved were still in controlled environment (jail, custody or residential treatment).

Discussion

The present study is a naturalistic study on those who applied for OMT. The preconditions for this population was indeed problematic, given that they had failed several addiction treatments before. Previous studies on the baseline data of this population showed severe dependence problems in diagnostic terms and in all related areas [29,30]. The study´s main findings are that improvements are strongly related to the trajectories of the OMT process. Since the trajectory groups shared similar characteristics in age, gender, previous treatment experiences and follow-up-time, the outcome findings could not be explained from these factors.

Those who were not admitted had—on group level—no significant improvements in any of the eight prospective measures or in any of the eleven retrospective measures. Still, there was variation in outcomes with individual improvements for some who had successful referrals and impairments for those not referred.

Those admitted but then discharged showed moderate improvements in drug problems according to the prospective measures. Using the retrospective measures there were significant changes in all 11 areas, strong in opioid drug use, moderate in others. A closer look, however, related most improvements in this group to those being in controlled environment (jail, custody or residential treatment). Therefore, it remains to be seen how stable these changes are.

Both groups in OMT (readmitted and remained) had better improvements than those outside OMT (denied and discharged). Those readmitted showed strong improvement in drugs and moderate in legal status and alcohol according to prospective measures, while retrospectively, they improved significantly in all measures, and strongly so in seven areas.

Most profound improvements were found among those with uninterrupted OMT, with strong prospective change in drugs, moderate in legal and psychiatric status, while modest concerning housing and relations. Retrospectively, they recorded improvements in all areas, and strong such in as many as nine.

There are – as might be expected – differences between prospective and retrospective measures in most trajectories. The ASI is an established and validated measure on drug and related problems and using that prospectively is the most conservative method of the two. Retrospective measures may be problematic in terms of evaluating past experiences, and therefore least trustworthy. On the other hand, these measures are constructed to measure the problem areas separately, without mixing employment and economy, legal problems and criminality, and various types of drugs and relations. Therefore, they may be more sensitive to capture these problems. Using one conservative and one more sensitive measure should provide some differences. Both methods however agree on the general pattern: the more involved patients were in OMT, the more improvements were found. Thus, the improvements were mostly found in the two groups actively involved in OMT at follow-up. The results are compatible with previous research showing that persons with extensive opioid-dependency problems benefit from being in OMT.

These findings should be discussed in relation to the methodological limitation of those lost to follow-up interview: 28 out of 127 (22 per cent) could not be interviewed. Looking at the situation related to attrition, we found that all six who died due to causes related to ongoing substance use, and both those who were too unfit to be interviewed due to mental illness, belonged to the two trajectories least involved in OMT. These circumstances do not conflict with our findings—rather the opposite. Circumstances of attrition that clearly indicate a negative process are only found in those trajectories which are least involved in OMT.

However, OMT is not the solution for everyone. Within the groups least involved in OMT, there were important individual examples of other ways to recover from severe misuse problems. Some recovered with support of other treatment, as did two persons without treatment but with extensive support from social networks such as church and family.

For those denied OMT or discharged,the study shows a high risk for overdoses in line with previous research [15], and it motivates offering extensive and well-tailored support and other treatment options to them [13]. Care providers should develop attractive forms of supplementary care or refer patients to such care provided by other organizations, if needed [19,37]. To prevent attrition, it is important to train staff in non-judgmental and non-confrontational communication strategies, and to reduce the waiting time for possibility to re-apply for OMT. Additional interventions based on the individual needs should include psychosocial support and comorbidity care [6,16,19,37].

Conclusions

This study provides further evidence of the effectiveness of OMT that adds to previous efficacy studies. It underscores the importance of dealing with two major risk factors/situations, i.e. being denied treatment, and being forced to leave treatment—even if these decisions are well motivated. A concern for care providers should be to develop tailored interventions also for these groups with increased risk.

Acknowledgments

We would like to acknowledge the invaluable help rendered by those interviewed, who spent time participating in this study without immediate benefit to themselves. We also want to thank PhD Mats Nilsson, Futurum – Academy for Health and Care, Jönköping County Council – for introducing us in Svensson’s method, and colleagues at the Dependency Clinic at County hospital Ryhov in Jönköping and at The National Board of Forensic Medicine in Linköping for their help and support.

Disclosure statement

None of the authors have interests related to this project other than research.

Additional information

Funding

The study was financed by a grant from FUTURUM, County Hospital Ryhov Jönköping [D.nr: FUTURUM-342201].