Design and setting
This study is a prospective cohort study based on data from consenting participants in the Norwegian THN programme from the period of June 2014 to June 2020. All individuals receiving THN were asked to complete questionnaires and provide consent to use their data for the study. Participation in the study was voluntary and did not preclude receiving THN. Because participants could receive THN without enrolling in the study, unique identification data were not captured on all participants at first distribution of kits. This reflected a decided priority in distributing naloxone over requiring complete registration and thus data collection from all participants.
The Norwegian THN programme is a widespread, government-supported public health initiative. The programme began as a pilot project in June 2014 as part of the National Overdose Prevention Strategy [15]. Details for the THN programme are described elsewhere [16]. Presently, the Norwegian THN programme is a national scheme, currently offering naloxone at 125 distribution sites across the country. Naloxone is distributed within the national overdose prevention scheme without individual prescription or cost to recipients.
Data collection consists of (ideally) an initial baseline questionnaire at the first training, followed by a refill questionnaire for all subsequent visits. A participant ID is generated using the first three letters of their last name and the first four digits of their birthdate. This ID was used to link baseline and refill questionnaires across sites. Data are collected by staff working at the distribution sites at the point of THN training [17]. Data collection began on paper in 2014 but transitioned to electronic data collection for all sites by 2018. Participation in data collection is voluntary, and individuals can receive naloxone without filling in the questionnaires (at any time point).
Measures
The measures examined come from two separate questionnaires. The measures obtained from the baseline questionnaire include gender, age, current opioid use (current, previous, never), number of witnessed overdoses (never, once, 2–10 times, 11–20 times, more than 20 times), and the number of experienced overdoses (never, once, 2–10 times, 11–20 times, more than 20 times). From the refill questionnaires, we obtained: the rescuer’s relationship to the person who overdosed (friend, acquaintance, partner, stranger, self, child, other), the overdose location (private home, shelter, on the street/public place, car/car park, other), number of reported THN saves, and number of returns for refills. This information did not overlap, and therefore, questions asked from the initial questionnaire were not repeated at subsequent refills.
Inclusion
Participants were included in this study if they returned one or more times for a refill and had provided data at baseline.
Supersaver
Supersavers are defined as individuals who returned for a refill three or more times during the study period and reported that the sprays had been used on an overdose. This dichotomization of supersavers (as those used THN three or more times) and not supersavers (those that used THN zero to two times) was made due to the spread of the data and the need for sufficient amounts in each group. There were no limits to how many times someone could obtain a refill from the THN programme.
Statistical analysis
Baseline demographic characteristics (gender, age, current opioid use status, number of witnessed overdoses, and number of experienced overdoses) are described for all participants. For witnessed overdoses, we describe the overdose location and the witnesses’ relationship to the person who overdosed. Pearson Chi-square tests were used to assess the relationship between different participant characteristics (gender, current opioid use, and number of witnessed and experienced overdoses) and reported THN use (‘not used’ against ‘used’ and ‘zero to two reports’ against ‘three or more reports’) for participants who provided baseline data and refill data. Independent samples t tests were used to compare age and reported THN use (‘not used’ against ‘used’ and ‘zero to two reports’ against ‘three or more reports’).
All analyses were completed in IBM SPSS version 27.
Ethical approval
This study was approved by the Norwegian Data Protection Official for Research.