Development and validation of a novel scale for measuring interpersonal factors underlying injection drug using behaviours among injecting partnerships

A Study of Sexual Relationship Power among Young Women Who Inject Drugs and Their Sexual Partners

BACKGROUND

To date, research applying the Sexual Relationship Power Scale (SRPS) has been limited to sexual risk behaviors.

OBJECTIVE

We measured levels of sexual relationship power and examined associations between sexual relationship power and injecting and sexual behaviors that place women at increased risk for blood borne infections.

METHODS

Using data from a cross-sectional study of young women who inject drugs (WWID) in San Francisco, USA, logistic regression analysis identified independent associations between SRPS and subscale scores (relationship control [RC] and decision making dominance [DMD]) and injecting and sexual behaviors.

RESULTS

Of the 68 young WWID, 24 (34%) reported receptive syringe sharing, 38 (56%) reused/shared a cooker to prepare drugs, and 25 (37%) injected someone else's drug residue during the three-months prior to enrollment. Most (60, 88%) reported condomless sex with main sex-partner, 8 (12%) reported transactional sex, and 36 (53%) had two or more recent sex partners. The median SRPS score was 2.98 (IQR: 2.65, 3.18), 3.23 (IQR: 3.23, 3.57) for RC and 2.40 (IQR: 2.20, 2.60) for DMD. No significant associations were detected between SRPS or DMD and injecting or sexual risk behaviors. After adjusting for gender and years injecting, for every one-point increase in RC, women had a 6.70 lower odds of recent condomless sex (95%CI: 0.92, 50.00, p = 0.06), and a 3.90 lower odds of recent transactional sex (95%CI: 1.22, 12.50, p = 0.02).

CONCLUSION

Our study findings suggest that some components of sexual relationship power may play a role in sexual risk, but not in injecting risk.

Best Practices for Developing and Validating Scales for Health, Social, and Behavioral Research: A Primer

Scale development and validation are critical to much of the work in the health, social, and behavioral sciences. However, the constellation of techniques required for scale development and evaluation can be onerous, jargon-filled, unfamiliar, and resource-intensive. Further, it is often not a part of graduate training. Therefore, our goal was to concisely review the process of scale development in as straightforward a manner as possible, both to facilitate the development of new, valid, and reliable scales, and to help improve existing ones. To do this, we have created a primer for best practices for scale development in measuring complex phenomena. This is not a systematic review, but rather the amalgamation of technical literature and lessons learned from our experiences spent creating or adapting a number of scales over the past several decades. We identified three phases that span nine steps. In the first phase, items are generated and the validity of their content is assessed. In the second phase, the scale is constructed. Steps in scale construction include pre-testing the questions, administering the survey, reducing the number of items, and understanding how many factors the scale captures. In the third phase, scale evaluation, the number of dimensions is tested, reliability is tested, and validity is assessed. We have also added examples of best practices to each step. In sum, this primer will equip both scientists and practitioners to understand the ontology and methodology of scale development and validation, thereby facilitating the advancement of our understanding of a range of health, social, and behavioral outcomes.