["Addiction, EarlyView. ", "\nAbstract\n\nBackground and aims\nIn low‐resource settings such as Cameroon, blood alcohol concentration (BAC) testing is rarely available for road traffic injury (RTI) patients, necessitating confidence in self‐reported alcohol use for screening purposes. While Western settings often rely on objective measures like BAC for identifying alcohol‐related RTIs, self‐reporting may be more viable in contexts with limited resources and different cultural norms. This study aimed to (1) compare self‐reported alcohol use with breathalyzer‐confirmed BAC results and (2) identify factors associated with BAC positivity among RTI patients.\n\n\nDesign\nThis was a cross‐sectional study of RTI patients conducted at two Cameroonian hospitals. Participants underwent structured interviews and breathalyzer testing upon presentation to the emergency department within six hours of injury.\n\n\nSetting\nLimbe Regional Hospital and Edea Regional Hospital Annex in Cameroon, both of which are part of the Cameroon Trauma Registry.\n\n\nParticipants\nA total of 305 RTI patients aged 21 years and older who had acute injuries were included. The median age was 35 years (interquartile range = 16). More than ¾ of the population were male (76.4%) and most resided in urban areas (74.4%).\n\n\nMeasurements\nSelf‐reported alcohol use within six hours of injury was compared with breathalyzer‐measured BAC (threshold ≥0.01%). Diagnostic metrics [sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV)] were calculated, and multivariable logistic regression was used to assess predictors of BAC positivity.\n\n\nFindings\nSelf‐reporting had a sensitivity of 84.3% and specificity of 71.1%. The NPV was high (93.8%), while the PPV was low (46.5%). Non‐detection of BAC in positive self‐report cases was common: 73.1% of those reporting 1–2 drinks were BAC‐negative, but all who reported >2 drinks were BAC‐positive. In adjusted models, male sex [adjusted odds ratio (AOR) = 3.99, 95% confidence interval (CI) = 1.4–13.6], alcohol use disorder (AOR = 8.11, 95% CI = 3.3–21.6) and nighttime injury (AOR = 4.42, 95% CI = 2.1–9.5) were independently associated with BAC positivity.\n\n\nConclusions\nIn Cameroon, self‐reported alcohol use appears to be a practical and sensitive tool for ruling out non‐drinkers and identifying high‐risk road traffic injury patients, especially where blood alcohol level testing is unavailable. Screening strategies targeting men, night hours and individuals with alcohol use disorder may enhance the implementation of interventions like screening, brief intervention and referral to treatment (SBIRT) in emergency care settings.\n\n"]