How long does a cough last? Comparing patients' expectations with data from a systematic review of the literature

We hypothesized that antibiotic overuse for acute cough illness (ACI) is in part due to a mismatch between patients' expectations and the natural history of ACI.

We performed a population-based random digit dialing survey of 493 adults in Georgia to determine their expectations regarding the duration of ACI. We also performed a systematic review of observational studies and the placebo or untreated control groups of randomized controlled trials to determine the duration of ACI from the published medical literature. We included studies of otherwise healthy adults with undifferentiated ACI, no clear bacterial cause, data on at least 1 cough outcome, and at least 1 week of follow-up.

The mean duration of cough in the published literature was 17.8 days. Survey respondents reported a median duration of 5 to 7 days and a mean duration of 7.2 to 9.3 days depending on the specific scenario. Patients expecting a longer duration of illness were more likely to be white, female, and have self-reported asthma or chronic lung disease. Independent predictors of the belief that antibiotics are always helpful included nonwhite race (OR = 1.82, 95% CI, 1.14-2.92), some college education or less (OR = 2.08, 95% CI, 1.26-3.45), and previous antibiotics for ACI (OR = 2.20, 95% CI, 1.34-3.55).

There is a mismatch between patients' expectations regarding the duration of ACI and the actual duration based on the best available evidence. Efforts to reduce inappropriate antibiotic use should target this discrepancy.