Development and Validation of a Protective Behavioral Strategies Scale for Individuals who use Opioids: Preliminary Findings and Future Directions

Background: Protective Behavioral Strategies (PBS) are individually implemented harm reduction (HR) strategies to reduce the frequency or severity of risks associated with drug use. Existing scales measuring PBS for alcohol and cannabis suggest PBS are associated with reductions in associated problems. Despite many HR strategies related to opioid use, no PBS scale has been developed in the context of opioid use. To address this gap, this study aimed to test and validate a PBS scale for individuals using opioids (PBSO). Methods: An online survey utilized a 32-item PBS scale for individuals endorsing recent opioid use, and measured opioid use frequency, HR service use, and experience of opioid overdose. PBSO items were rated on a Likert scale ranging from “never” (0) to “always” (6), and an exploratory factor analysis (EFA) examined factor structure. Results: In the current sample (n=499; 32% female), EFA suggested a 3-factor structure among the 28 items retained, accounting for 51% of total variance. Factor 1 reflected health-service seeking, Factor 2 reflected individually-implemented and dose-reduction strategies, Factor 3 reflected social strategies, and Factor 4 reflected strategies related to injection drug use. Endorsement of PBSO items were slightly above “occasional” (3). PBSO use appeared positively related to past-month HR service utilization and negatively related to opioid use frequency. Conclusions: Findings provide preliminary support for the PBSO scale as a valid and reliable measure. Further work is needed to test this scale in larger samples, and future work should explore the association between PBSO and relevant health outcomes, and whether factor scores differentially impact these outcomes.


Introduction
The U.S. opioid overdose (OD) crisis has reached historic levels and continues to evolve.An estimated 79,117 Americans died from an opioid-related OD in the rst nine months of 2022 (CDC Wonder, 2023), and approximately 2.7 million Americans meet criteria for opioid use disorder (OUD) each year (CDC/NCHS, 2022 a ; CDC/NCHS, 2022 b ).Medications for OUD (MOUD) protect against overdose, reduce opioid use, and improve health outcomes; however, only a fraction of those with OUD access, initiate, or remain engaged in treatment, with some estimates suggesting that nearly 90% of those who may bene t from medication for OUD (MOUD) do not receive it ( unable to access or not engaged with MOUD (Krawczyk, 2022), an increased focus is needed on harm reduction (HR) service implementation for those with OUD and other substance use disorders.
Broadly, HR provides tools, resources, and strategies for individuals who use drugs that can help mitigate risks associated with drug use, regardless of an individual's interest in or engagement with formal treatment (Single, 1995; National Harm Reduction Coalition [NHRC], 2020).In the context of OUD, common HR strategies include syringe access, overdose education and naloxone distribution (OEND), access to testing for infectious diseases, and more recently in the U.S., overdose prevention centers (OPCs).Research supports the role of HR in reducing OD deaths and providing a platform for connecting individuals with vital health and social resources, as well as offering linkage to treatment for those who are interested (Nassau et

Materials and Methods
Participants were recruited for a one-time web-based survey via Reddit, Bluelight, and yers posted in the New York State Psychiatric Institute (NYSPI).An initial pool of participants was recruited with an incentive of entering a ra e to win one of eight $50 gift cards.A second pool of participants was recruited with an incentive of entering a ra e to win one of ninety-ve $10 gift cards.All study procedures and survey questionnaires were approved by the NYSPI Institutional Review Board.After providing consent to participate, participants were queried about past-month use of PBS, patterns of opioid use, and pastmonth HR service utilization.Prior to initiating the survey, participants were asked to con rm that they were at least 18 years old and had used opioids or MOUD within the last 3 months.Participants who completed the survey were provided an option to be redirected to a separate survey to enter their email address for ra e entry and gift card eligibility.Survey responses were therefore collected in an entirely separate survey than potentially identifying information (email address).

1 Measures
The or drugs from a trusted source, avoiding mixing opioids with other drugs, avoiding driving while intoxicated, and using a small amount before using more.As with prior versions of the PBS, participants were instructed to rate past-month engagement in each behavior on a 6-point Likert scale ranging from never (0) to always (6), or to select N/A for items not relevant or applicable (e.g., items about IDU for those who don't use drugs intravenously).The PBSO also included one attention-check question, on which participants were instructed to select "occasionally (3)".For a full list of items included in the PBSO, see Table 2.One open-ended question followed presentation of the PBSO to allow participants to share additional strategies they did not feel were captured by the scale.
Demographic Data.Participants were asked to provide their age, race, ethnicity, gender identity, and state in which they resided.
Opioid Use.Participants were asked to describe current opioid use with emphasis on route of administration, frequency of use (days per week), typical amount of money spent on opioids per occasion (in U.S. dollars), experience of opioid overdose (OD), and connection with a treatment provider.
Past-Month HR Service Utilization.Participants were presented with a list of 11 common HR services and asked to select which they had accessed in the past month.Items included: obtaining naloxone, attending a naloxone training, sterile injection supplies such as syringes, safe smoking supplies, wound care, screening for HIV and Hepatitis C infections, use at an overdose prevention center, accessing pre-exposure prophylaxis (PrEP) or post-exposure prophylaxis (PEP), and accessing fentanyl test strips.
Additionally, an open-ended question was included to capture any past-month HR service utilization not listed above.

Statistical Analyses
Data analyses were conducted in RStudio 2023.3.0.Means and standard deviations were calculated for all quantitative variables, and frequencies and percentages were calculated for categorical variables.Internal consistency of the PBSO was assessed using Cronbach's alpha and split-half reliability estimates.Bivariate correlations and linear regression were used to assess associations between PBSO scores and opioid use, opioid OD, and past-month HR service utilization.Prior to running the initial exploratory factor analysis (EFA), Bartlett's test of sphericity and the Kaiser-Meyer-Olkin test were used to con rm appropriateness for EFA.An initial EFA was conducted to determine which (if any) items should be dropped and a nal EFA was conducted with the set of remaining items.Based on prior recommendations for EFA (Tabachnick and Fidell, 2007), items with low loadings (< 0.32) or relatively strong loadings (≥ 0.32) on two or more factors (i.e., cross-loadings) were dropped from further analyses.

Results
A total of 1,056 individuals initiated/opened the survey with 293 participants not responding to a single question after the survey consent page.An additional 256 participants provided invalid responses, or responses in a language other than English, and were therefore not included in the present analyses.An additional eight participants incorrectly responded to the attention-check question and were removed from analyses.Therefore, a total of 499 valid responses were included in the present analysis.
Participants endorsed using opioids an average of 3.9 (SD = 2.0) days per week, with 11% of participants (n = 51) only endorsing prescribed MOUD use.Of the remaining 411 participants endorsing heroin, fentanyl, or non-prescribed opioid use, 33% (n = 152) endorsed intravenous use, 21% endorsed oral use (n = 97), 19% endorsed intranasal use (n = 89), and 16% endorsed using by inhalation (n = 73).All demographic and drug use questions were optional (no forced responding) to allow for greater participant autonomy and choice in which questions were answered.Therefore, while there were 499 valid survey responses, not every question had 499 responses.
The maximum possible endorsement of PBSO in the current survey was 192.On average, participants had a mean score of 105.2 (SD = 30.8)suggesting a frequency of endorsement slightly above "occasional".See Table 1 for average endorsement of each PBSO item.The maximum possible endorsement for past-month HR service utilization was endorsement of all 11 items.Participants in the current sample endorsed using an average of 2.4 (SD = 2.0) HR strategies in the past-month.

1 Psychometric Properties of the PBSO
Cronbach's alpha for the PBSO in the current sample was 0.95, suggesting high internal consistency.Split half reliability in the current sample was 0.96, also supporting high internal consistency.

Exploratory Factor Analysis (EFA)
Bartlett's test of sphericity was statistically signi cant (p < 0.001), suggesting that the data were appropriate for factor analysis.The Kaiser-Meyer-Olkin measure of sampling adequacy (0.92) indicated that the sample size was adequate and appropriate for factor analysis.
In the initial EFA, 26 items had loading < 0.40, while four items demonstrated cross-loading (loadings < 0.32 on more than one factor), and one item did not demonstrate t with any factor.These ve items were dropped, and a second EFA using principal axis extraction and oblimin rotation was used for the remaining 26 items.Five factors were detected with eigenvalue factor loadings greater than or equal to 1.0 (eigenvalues = 10.38,2.09, 1.69, 1.25, and 1.15).Examination of the scree plot along with parallel analysis supported a 5-factor structure of the PBSO, accounting for 54% of total variance.Examination of correlations between factors suggested a level of association appropriate for oblimin rotation and RMSR (0.02), RMSEA (0.03), and TLI (0.986) all suggested adequacy of the factor model.
Examination of the pattern matrix suggested that ten items mapped onto Factor 1 (accounting for 18% of total variance), seven items mapped onto Factor 2 (11% of total variance), four items mapped onto Factor 3 (10% of total variance), four items mapped onto Factor 4 (10% of total variance), and two factors mapped onto Factor 5 (6% of total variance).The rst factor appeared related to health-service seeking or "external" strategies that individuals had to proactively seek out (attending training on OD prevention, fentanyl test strips, accessing wound care, etc.).The second factor appeared related to internally implemented and dose-reduction strategies (sampling a small amount before using more, avoiding mixing drugs, buying a set amount, etc.).The third factor related to social strategies (taking turns when using with others, ensuring use partners have access to and know how to use naloxone, etc.).The fourth factor contained items related to IDU (avoid shared needles, always using new needles, using clean works, disposing of needles safely).Finally, the fth factor related to testing for HIV and Hepatitis C. See Table 1.
Though the observed SRMR (0.07) indicated good t, the RMSEA re ected a marginal t (0.09), and remaining indices did not demonstrate a good t.All factor loadings in our model were signi cant at p < 0.00.Given the poor t of the model, additional work is needed to validate and con rm a 5-factor structure or identify other factor structures.

Criterion Validity: Association between PBSO and other measured outcomes
Bivariate correlations were used to examine the relationship between PBSO endorsement and other outcomes.Endorsement of PBSO and past-month HR service utilization were moderately correlated (r = .50),and a linear regression suggested a signi cant association between these variables (F (497, 1) = 145.7,p < .0001,r 2 = .23).A small but statistically signi cant negative correlation was observed between PBSO score and days of opioid use per week (r = − .21;p < 0.001), with a signi cant association (F(368, 1) = 16.26,p < 0.001, r 2 = .04).Similarly, PBSO score was signi cantly negatively correlated with self-reported lifetime number of opioid overdoses (r = − 0.20; p < .001),but no signi cant regression was observed between these variables.

Responses to Open-Ended Question
Following of above PBSO items, participants were presented with an open-ended question that asked, "What are some other strategies that you use to keep yourself safe while using opioids or other drugs?".One-hundred and forty-four participants provided a response to this question.Responses were coded independently by MG and RL and coding schemes were compared and re ned to reach a nal coding scheme.Responses were coded based on content and 65% of responses (n = 94/144) noted strategies already captured in the scale.For example, within these responses, participants mentioned buying from one source, ensuring access to naloxone, avoiding mixing opioids with alcohol, use of new needles, using with others rather than alone, etc.Three additional respondents indicated that all PBS strategies were adequately included in the scale.Of the 144 responses, 84 responses were coded as containing more than one theme.Identi ed themes included: controlling the dose or using only small amounts (n = 44), setting a limit on the amount used or the timeframe of use in a given day (n = 27), use of MOUD (n = 8), only using at home or avoiding use in public places (n = 6), use of disinfectants (n = 9), use in a rescue position (n = 3), avoiding fentanyl (n = 10), altering route of administration to reduce risk (n = 7), use of a pulse oximeter (n = 2), and seeking out knowledge from other individuals using drugs or online communities about the drug supply (n = 11).

Discussion
The current study sought to develop, validate, and explore the factor structure of a brief, self-report scale measuring PBS in the context of opioid use (PBSO).An initial EFA of the 32-item PBSO developed for the present study suggested a 5-factor structure, with one item that did not load onto any extracted factors, and four items demonstrating cross-loading.These factors were dropped and a second EFA on the remaining 26-items also suggested a 5-factor structure, accounting for 51% of the total variance.Extracted factors appeared to correspond to health-service seeking or extrinsic strategies (Factor 1), individually implemented and dose-reduction strategies (Factor 2), social strategies (Factor 3), and IDU-related strategies (Factor 4).The PBSO scale adapted for the current study demonstrated high internal consistency, and appears to be a reliable measure, though further work should continue to validate this scale in larger, more ethnically and gender-diverse samples.Initial examinations of validity of the PBSO suggest PBSO scores are signi cantly positively associated with past-month HR service utilization.This suggests that with further validation, the PBSO scale may provide a helpful tool for understanding engagement in protective or buffering strategies for those who use opioids.Further, analyses suggest that PBSO scores may be negatively related to frequency of opioid use and the total number of self-reported opioid overdoses, again providing preliminary evidence for the validity of the PBSO.

Conclusions
As (Martens et al., 2005)Strategies Scale(Martens et al., 2005)was adapted for opioid use in the current survey, resulting in a 32-item PBS for Opioids (PBSO) scale.Items for the PBSO were selected based on prior versions of the PBS for alcohol and cannabis, and a review of HR strategies common among those with OUD and/or injection drug use (IDU) by authors RL, SM, MG, and SD.Authors reviewed published literature on HR for OUD(Nassau etal., 2022; Puzhko et al., 2022), as well as guidelines published by organizations such as the National Harm Reduction Coalition (NHRC; NHRC, 2020), Faces and Voices of Recovery (2019), Health and Human Services (HHS, 2022) Substance Abuse and Mental Health Services Administration (SAMHSA, 2023), and the National Institute on Drug Abuse (NIDA, 2022).In reviewing these sources, several themes emerged that were used in developing items speci c to OUD or adopting items used by prior, validated PBS scales.Speci cally, items focused on overdose prevention training and access to naloxone, education and resources focused on IDU and infectious diseases, syringe exchange and safe consumption strategies, utilization of MOUD, use of fentanyl test strips, and social or dose-control strategies observed among individuals with OUD (CITE).Strategies adapted directly from other validated PBS scales included purchasing opioids

Table 2 :
(Martens et al., 2005) to develop and test the PBSO, further work is needed to validate this scale in larger, more diverse samples, and efforts to coadminister the PBSO in settings where objective measurement of opioid use, opioid overdose, and other relevant clinical outcomes is warranted.Though compelling, this work is not without limitations.First, survey respondents include individuals using opioids recreationally, individuals only reporting MOUD use, and individuals reporting MOUD and non-prescribed opioid use.While this represents a wider population of individuals with opioid use, the way questions were asked did not allow us to accurately conduct item variance testing based on opioid use group.Future work incorporating the PBSO into settings where opioid use type can be objectively measured and further categorized would allow for invariance testing, which was not possible in the current sample.Future work exploring whether factor scores differentially relate to relevant health outcomes is also warranted.As prior PBS scales were rst developed and implemented in non-clinical settings(Martens et al., 2005), future work must consider PBSO in the context of individuals with OUD or clinically signi cant problems associated with opioid use.Declarationsapproval and consent to participate: Study procedures were reviewed and approved by the NY State Psychiatric Institute Institutional Review Board (IRB #8351).Prior to survey-initiation, participants were presented with IRB-approved consent script outlining the purpose and voluntary nature of the survey, risks/bene ts, con dentiality, the PI's contact information, and the IRB's contact information.PBSO Items and EFA Results