Variables used in the imputation process.

BackgroundAlcohol use contributes to over 3 million deaths annually. In Tanzania, there are no evidence-based culturally adapted interventions to address harmful alcohol use behaviors. Our hypothesis was that “Punguza Pombe Kwa Afya Yako” (PPKAY, Reduce Alcohol for your Health), a culturally adapted brief intervention with text-based boosters, is superior to usual care in reducing binge drinking at 3 months post discharge.Methods and findingsThis manuscript reports. Stage 1 of our adaptive clinical trial which seeks to determine the effectiveness of the PPKAY+ booster to usual care; a subsequent stage will compare the PPKAY only to personalized and standard boosters. Adults who sought care for an acute injury at the Kilimanjaro Christian Medical Centre Emergency Department, self-disclosed alcohol use prior to the injury, scored ≥8 on the Alcohol Use Disorder Identification Test, and/or test positive by alcohol breathalyzer were offered enrollment. Participants were randomly assigned to PPKAY+ boosters (personalized or standard) or usual care at 1:1:1 allocation. Primary analyses followed the intention-to-treat principle. The PPKAY is a 15-min nurse delivered brief intervention using motivational interviewing techniques combined with a standardized or personalized text based reminder sent weekly to participants after hospital discharge and until 1 year post enrollment compared to a usual care arm. Follow-up was performed by blinded outcome assessors. Our pooled intervention arms PPKAY+ boosters were compared to usual care to determine the effectiveness of the intervention in reducing the number of binge drinking days, the trial’s primary outcome, in the previous 4 weeks at 3 months after discharge. A total of 1,484 patients were screened for eligibility between October 12th 2020, and on April 14th 2023. 448 patients met inclusion criteria and consented to participate. 148 were randomized to usual care, and 300 to the pooled intervention arm. Reasons for attrition included loss to follow-up (n = 69), withdrawal (n = 6), and deaths (n = 4), with no differences between arms. Most participants were male (94%), from the Chagga tribe (59%) and had an average age of 36.4 years (SD 12.6) at baseline. At the 3-month follow-up, the intervention arm showed a notable reduction in mean predicted binge drinking days by 1.2 days (95% CI: [−2.3, −0.3]; p = 0.002) compared to the usual care group in a difference-in-differences analysis. Importantly, the self-reported nature of our primary outcome introduces the potential for social desirability bias, particularly in the absence of participant blinding, and should be considered a limitation when interpreting the findings.ConclusionThe reduction in binge drinking behavior at 3-month follow-up compared to usual care suggests our culturally adapted intervention is an effective alcohol intervention for patients acutely injured in Tanzania. According to the adaptive study design, the next phases of the trial will continue to compare the intervention arm with a paired down version without the text messages boosters.Trial registration numberClinicalTrials.gov NCT04535011