To obtain arm and finger measurements of women ≥32 weeks gestation to determine: the requirement for different arm cuff sizes; the suitability of available finger cuffs in this population; the best predictor of arm conicity; the frequency of cuff placement on the forearm or leg. Study Design Prospective observational pilot study. Main outcome measures Right and left mid-arm circumference (MAC) and to compare these to the recommended cuff sizes; right and left finger circumference; right and left arm conicity; the responses of women to a three-point Likert scale regarding cuff placement. Results Measurements were obtained for 450 women at an Australian tertiary hospital with a median (IQR) gestation of 35.7 (34.0-37.0); 299 (66.4%) were Caucasian and 35 (7.8%) had gestational hypertension. The median (IQR) body mass index (BMI) was 29.6 kg/m 2 (26.2-33.4), range 18.0-62.2. Median (IQR) right MAC was 29.9 cm (27.4-33), range 19.6-53.2. Based on right MAC, 58 (12.9%) required a large cuff and 6 (1.3%) a thigh cuff. Maximum right finger circumference was 7.0 cm. BMI, weight and right MAC were positively correlated with right arm conicity: r=0.51, 0.42 and 0.45, p<0.001 for all. R 2 for each were 0.26, 0.17 and 0.20. Fourteen (3.1%) reported cuff placement on the forearm or leg. Conclusions Page 4 of 23 A small percentage of women are likely to be unsuited to traditional arm cuffs. Available fingercuffs would suit this population. BMI could potentially be used to select women with coneshaped arms for future studies of alternative devices.

Background: People who inject drugs (PWID) are at greater risk of developing bacterial skin and soft tissue infections (SSTI) than the general population. UK prevention interventions have achieved limited impact on the rising prevalence of SSTI among PWID. Innovative harm reduction interventions are needed. We present our approach to the co-development of a personalised, behavioural intervention, REACT (REducing bACTerial infections), which aims to prevent bacterial SSTI among PWID.Methods: We followed the interrelated steps of the Person-Based Approach for intervention planning and development: (i) collating evidence, including published literature and consultations with PWID (n=15), service providers (n=6), and stakeholders (n=11); (ii) developing guiding principles; (iii) undertaking a behavioural analysis; (iv) developing a logic model, and; (v) designing and refining intervention materials. Results: Published literature highlighted structural barriers to safer injecting practices, such as access to hygienic injecting environments, homelessness and social exclusion. Practices associated with bacterial SSTI included: (i) handwashing / injection-site swabbing; (ii) overuse of acidifier; (iii) use of non-sterile water for injection preparation; (iv) reuse of injecting equipment; and; (v) lack of injecting site rotation. Consultations indicated vein care and minimisation of pain as priorities, while emphasising the importance of service provider-client relationships during intervention delivery. The need to deliver REACT in a non-judgemental and non-stigmatising manner, and to address stigma among PWID when communicating intervention messages, were additional priorities. Providing practical, tailored resources was identified as important to address environmental constraints to safer injecting practices. Findings were used to iteratively refine the REACT intervention. Conclusion: Our evidence-based, collaborative and iterative approach, enabled alignment of the aim of the behavioural intervention to priorities of PWID, ensuring an appealing and acceptable intervention design while maximising likely feasibility of delivery and behaviour change. Piloting will establish the feasibility and acceptability of REACT to service providers and PWID.