PT  - JOURNAL ARTICLE
AU  - Mark H Ebell
AU  - Isabella Locatelli
AU  - Yolanda Mueller
AU  - Nicolas Senn
AU  - Kathryn Morgan
TI  - Diagnosis and treatment of community-acquired pneumonia in patients with acute cough: a quantitative study of decision thresholds in primary care
AID  - 10.3399/bjgp18X699545
DP  - 2018 Nov 01
TA  - British Journal of General Practice
PG  - e765--e774
VI  - 68
IP  - 676
4099  - http://bjgp.org/content/68/676/e765.short
4100  - http://bjgp.org/content/68/676/e765.full
SO  - Br J Gen Pract2018 Nov 01; 68
AB  - Background Test and treatment thresholds have not yet been described for decision-making regarding the likelihood of pneumonia in patients with acute cough.Aim To determine decision thresholds in the management of patients with acute cough.Design and setting Set among primary care physicians attending meetings in the US and Switzerland, using data from a prospective cohort of primary care patients.Method Clinical vignettes were used to study the clinical decisions of physicians regarding eight patients with cough that varied by six signs and symptoms. The probability of community-acquired pneumonia (CAP) was determined for each vignette based on a multivariate model. A previously published approach based on logistic regression was used to determine test and treatment thresholds.Results In total, 256 physicians made 764 clinical decisions. Initial physician estimates systematically overestimated the likelihood of CAP; 75% estimating a higher probability than that predicted by the multivariate model. Given the probability of CAP from a multivariate model, 16.7% (125 of 749) changed their decision from ‘treat’ to ‘test’ or ‘test’ to ‘rule out’, whereas only 3.5% (26/749) changed their decision from ‘rule out’ to ‘test’ or ‘test’ to ‘treat’. Test and treatment thresholds were 9.5% (95% confidence interval (CI) = 8.7 to 10.5) and 43.1% (95% CI = 40.1 to 46.4) and were updated to 12.7% (95% CI = 11.7 to 13.8) and 51.3% (95% CI = 48.3 to 54.9) once the true probability of CAP was given. Test thresholds were consistent between subgroups. Treatment thresholds were higher if radiography was available, for Swiss physicians, and for non-primary care physicians.Conclusion Test and treatment thresholds for CAP in patients with acute cough were 9.5% and 43.1%, respectively. Physicians tended to overestimate the likelihood of CAP, and providing information from a clinical decision rule (CDR) changed about 1 in 6 clinical decisions.