Knowledge about infections is associated with antibiotic use: cross-sectional evidence from the health survey Northern Ireland

BACKGROUND: Antibiotic overuse is the main modifiable driver of antibiotic resistance. Factors associated with overuse have been inconsistently reported and vary across populations. Given the burgeoning occurrence of infectious diseases around the world, there remains a great need to identify barriers and solutions to the control of infections. We examined whether knowledge about infections and antibiotic resistance is associated with antibiotic use in a northern European population sample. METHODS: The Health Survey Northern Ireland 2014/15 was completed by a cross-sectional sample of 4135 participants aged > 16 years. Participants were asked whether they had taken an antibiotic in the past 12 months; and six questions were asked concerning knowledge about infections and antibiotic resistance. Correct answers to the six knowledge questions defined a knowledge score (score range 0–6 correct answers). We used multivariable logistic regression to estimate odds of self-reported antibiotic use during the last 12 months in association with knowledge score (lowest score, 0/6, as referent), and response to each knowledge question. Covariates included sex, age group, smoking, alcohol drinking, deprivation index, self-rated health, and satisfaction with life. Results were outputted as Odds Ratios (OR) and 95% Confidence Intervals (CI). RESULTS: Antibiotic use in the past 12 months was reported by 39.0% (1614/4135); and 84.2% (3482/4135) scored < 6/6 correct on knowledge statements. Compared to the lowest knowledge score (0/6 correct), the highest knowledge score (6/6 correct) was associated with higher odds of antibiotic use (adjusted OR 2.03, 95% CI [1.46, 2.81], p < 0.001), with a P-value < 0.001 for trend with increasing knowledge score. Female sex, age, high deprivation, and poor general health, were independently associated with higher odds of antibiotic use. Stratified analyses showed sex and age group differences. CONCLUSION: Knowledge, and other modifiable and non-modifiable risk factors, were positively associated with antibiotic use in the past 12 months. While the causal direction of these associations could not be determined, given the high prevalence of lesser knowledge, as well as independent contributions of other factors including socioeconomic characteristics, health literacy campaigns to raise awareness of antibiotic resistance should take a multi-pronged approach. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-021-11018-x.