Predicting the onset of hazardous alcohol drinking in primary care: development and validation of a simple risk algorithm

Abstract

Background: Little is known about the risk of progressing to hazardous alcohol use in abstinent or low-risk drinkers.

Aim: To develop and validate a simple brief risk algorithm for the onset of hazardous alcohol drinking (HAD) over 12 months for use in primary care.

Design and setting: Prospective cohort study in 32 health centres from six Spanish provinces, with evaluations at baseline, 6 months, and 12 months.

Method: Forty-one risk factors were measured and multilevel logistic regression and inverse probability weighting were used to build the risk algorithm. The outcome was new occurrence of HAD during the study, as measured by the AUDIT.

Results: From the lists of 174 GPs, 3954 adult abstinent or low-risk drinkers were recruited. The 'predictAL-10' risk algorithm included just nine variables (10 questions): province, sex, age, cigarette consumption, perception of financial strain, having ever received treatment for an alcohol problem, childhood sexual abuse, AUDIT-C, and interaction AUDIT-C*Age. The c-index was 0.886 (95% CI = 0.854 to 0.918). The optimal cutoff had a sensitivity of 0.83 and specificity of 0.80. Excluding childhood sexual abuse from the model (the 'predictAL-9'), the c-index was 0.880 (95% CI = 0.847 to 0.913), sensitivity 0.79, and specificity 0.81. There was no statistically significant difference between the c-indexes of predictAL-10 and predictAL-9.

Conclusion: The predictAL-10/9 is a simple and internally valid risk algorithm to predict the onset of hazardous alcohol drinking over 12 months in primary care attendees; it is a brief tool that is potentially useful for primary prevention of hazardous alcohol drinking.

Keywords: alcohol consumption; clinical prediction rule; primary health care.

Figure 1.

Flowchart of patients through the predictAL-10/9 study and numbers becoming hazardous alcohol drinkers. AUDIT (Alcohol Use Disorders Identification Test). Hazardous alcohol drinking (males: AUDIT ≥8; females: AUDIT ≥6). Abstinent or low-risk drinkers (males: AUDIT <8; females: AUDIT <6); DNA = did not attend; T0 = at baseline; T6 = at 6 months; T12 = at 12 months.

Figure 2.

Calibration plots (mean predicted probability against observed probability of hazardous alcohol drinking within deciles of predicted risk) of the predictAL-10/9 risk algorithms.