Opioid-related mortality is high and increasing in the Western world and constitutes a significant public health challenge [1, 2, 3, 4, 5, 6]. As in many other Western European countries, opioid-related mortality has increased continously in Sweden over the past two decades [7, 8]. It is well established in the research that mortality among opioid-dependent individuals decreases when opioid substitution treatment (OST) is initiated and that mortality is lower for those who stay in such treatment compared to those who discontinue it [9, 10, 11, 12]. Less is known about the impact of OST on opioid mortality in communities at large, for instance whether increased access to OST reduces such mortality at an aggregate level.
In Sweden, OST has for a long time been conducted with a distinctly rehabilitative ambition and with restrictions on the number of patients receiving treatment. In the case of repeated relapses, treatment has often been terminated through involuntary discharge , a practice supported by national regulations. Tendencies towards a more harm reduction-oriented OST have been noted during the 2010s, however, especially in some parts of the country [14, 15]. In parallel with this, both the number of care providers and the number of patients in treatment have increased [16, 17, 18].
In the county of Skåne (Scania) in the south of Sweden, there has been a particularly sharp increase in recent years in both the availability of OST and the level of retention in treatment. These changes can partly be attributed to the introduction of a patient choice reform for OST in Skåne in 2014, which led to a marked increase in the number of places in OST in the region, and partly to changes in practice and regulations within OST since the mid-2010s [16, 19].
High-threshold and low-threshold OST settings
OST can be conducted in many ways, with variations being found both between and within countries. One commonly used distinction is that between programs that diverge in their views on strictness in the treatment setting, known as high-threshold and low-threshold OST.
High-threshold programs are typically characterized by an idea of rehabilitation, with complete abstinence from illicit drugs (and in some settings alcohol) being required for participation in OST. Exclusion through involuntary discharge follows (repeated) relapses into use or abuse of such substances. Follow-ups of patient compliance in treatment are frequent in the form of supervised on-site drug administration and supervised urine tests. Access to the treatment is often provided through specialist care only. Admission criteria are inflexible and waiting lists are often long due to restrictions on the number of treatment places [20, 21].
Typical low-threshold programs are described as being more harm-reduction oriented, and in contrast to high-threshold programs they do not require abstinence from drug use as a condition of service use. Relapses are expected and strategies to cope with relapses are therefore outlined. Low-threshold programs aim to reduce barriers to service access, such as waiting lists, and advocate more flexible admission criteria, treatment that is free of charge to the patients, and access to OST through both specialist and primary care providers. Low-threshold OST settings are also characterized by less frequent supervision of drug administration and less focus on urine testing as a means of following up patients’ compliance with treatment .
OST in Sweden and Skåne
OST was introduced in Sweden in the late 1960s and has for a long time been implemented within a high-threshold paradigm [14, 15, 22]. Sweden’s restrictive stance on the regulation of OST was traditionally characterized by limitations on the number of patients in treatment, strict admission criteria, and an abstinence-based view on relapse during treatment. In addition to waiting lists to access treatment, a suspension period was applied following involuntary discharge, which prevented patients from seeking treatment again before the specified period had elapsed [17, 23]. Apart from limitations on the length of treatment and costs for medication, which are often represented in high-threshold OST but do not apply to Swedish programs, OST in Sweden has generally been conducted based on the features that commonly characterize high-threshold and abstinence-based programs.
However, a gradual change has taken place in Swedish OST over recent years towards low-threshold and more harm-reduction oriented OST programs. This change has been particularly evident in Skåne County in southern Sweden . In 2014, the Skåne Regional Council implemented a patient choice reform for OST. The main aims of the reform were to increase access to treatment by permitting private clinics to provide OST, and to strengthen the patients’ influence on their treatment conditions by letting them choose between treatment providers . In parallel with the implementation of the patient choice reform in Skåne, the national guidelines regulating OST were revised in 2016. These changes in the guidelines, towards a more tolerant approach to admission criteria and relapses during OST, were an adjustment to reflect the way OST practice had over time adopted a more lenient approach towards relapse and exclusion, which was particularly evident in Skåne. The suspension period following discharge from treatment was also finally abolished in this revision of the guidelines .
The patient choice reform led to a substantial increase in access to OST in Skåne, from 992 to 1453 patients in treatment between 2013 and 2016, an increase of 46%. The number of OST treatment clinics rose from eight to sixteen during the same period. The reform has also resulted in a somewhat larger geographical spread across the region, as the number of municipalities with OST clinics has increased. However, the three largest municipalities, which already had established OST clinics, accounted for 73% of the increase in the number of patients. The largest increase in patients in OST treatment occurred during the initial years of the patient choice reform. The possibility for patients to choose their treatment provider has also led to increased retention rates in OST. Dissatisfied patients can choose to change clinics rather than dropping out of treatment [16, 19].
Opioid-related mortality and OST
One ambition with the patient choice reform was that increased access to OST would reduce the number of opioid-related deaths in the region. Drug-related mortality in Sweden has increased sharply during the 2000s, and Swedish figures are high by comparison with other European countries [2, 7]. At least 80% of drug-related deaths are opioid related . Since there are no current estimates of the number of people with problematic opioid use, either in Sweden or Skåne, it is not possible to establish the size of the target population.
Low-threshold OST, characterized by rapid and generous access to OST and lower levels of restrictions that may lead to discharge, may result in a higher proportion of opioid-dependent individuals initiating OST and not then being involuntarily excluded from the programs [20, 25]. High participation and retention in OST among the population of opioid-dependent individuals is desirable in order to reduce the risks associated with untreated opioid dependence [11, 20]. As was mentioned above, changes towards more low-threshold treatment have been implemented at a later stage in Sweden than in many other western countries.
However, there are also objections to low-threshold programs. More liberal, harm reduction-based treatment contexts with a lower degree of control may pose a greater risk that patients in OST may divert their medication to drug users who are not in treatment [18, 26, 27, 28, 29]. A study on methadone-related deaths in Danish low-threshold OST settings found high prescribed doses of methadone and a high level of prescribed benzodiazepines among the deceased . Such factors may counteract OST’s purpose of preventing opioid-related deaths [11, 31]. Increased access to OST may be associated with both diversion and increased opioid mortality, as more individuals with problematic opioid use are given access to methadone and buprenorphine, but also with a reduced risk of overdose, if illegal demand decreases when the number of opioid-dependent individuals entering treatment increases [32, 33].
In this study, we investigate opioid-related deaths in Skåne before and after the implementation of the patient choice reform for OST based on mortality data at the regional and national levels. The objective of the study is to examine how the implementation of the patient choice reform may be associated with different aspects of opioid-related mortality. More specifically, we:
Examine the changes in total opioid-related mortality in Skåne, and whether the trend differs between areas with increased and unchanged access to OST. As mortality is lower among opioid-dependent individuals who receive OST than among those who use illegal opioids, it is plausible that increased access to OST might lead to reduced mortality in Skåne overall. This change would be most noticeable in municipalities in which there has been a marked increase in the number of treatment places.
Examine whether the proportion of deaths in Skåne related to OST medications has changed by comparison with deaths related to other opioids. Increased access to OST and a more low-threshold, harm reduction-oriented treatment approach may lead to an increased supply of OST medications on the illegal market, partly because a higher number of patients receive treatment, and partly because patients with a high risk of diversion may remain in treatment. At the same time, increased access to OST may lead to reduced demand for illicit OST drugs, as more individuals with problematic opioid use enter treatment.
Examine whether there has been a change in Skåne in the proportion of deceased individuals during ongoing OST. A transition to more low-threshold oriented treatment would be expected to lead to individuals who had previously risked involuntary discharge instead remaining in treatment. Considering the high risk of intoxication among individuals with problematic use of opioids and other illicit drugs who remain in OST, this would mean that deaths during ongoing treatment may have become more common after the reform (while the number of deaths among involuntarily discharged patients may have decreased).
Examine the development of drug-related mortality in Skåne in relation to the rest of Sweden. Increased access to OST in Skåne might be expected to lead to lower opioid-related mortality in Skåne in relation to the other regions of the country, in which no corresponding increase in access has taken place. This analysis serves to control for the general tendency of increasing drug-related mortality that has been noted in Sweden during the last two decades.