Fig. 4

Likelihood ratios and probability plot for diagnostic tests in diagnosing different bacterial infections. Legend – a–d show likelihood ratios and pre- and post-test probabilities for diagnostic tests in diagnosing different bacterial infections. When possible, age-specific estimates have been given. When not specified, the result applies to patients aged 65 years and above. The figures have been separated according to the type of bacterial infection under investigation. Positive and negative likelihood ratios with 95% confidence intervals are presented for each test. The black dot within the dumbbell plot represents the pre-test probability of infection (i.e. disease prevalence). The red dot represents the probability of the infection after a positive test, and the green dot represents the probability of infection after a negative test. c – Estimates derived from people aged 80 years and above. d – CRP > 4.355 mg/L and WBC > 8,500/mm³ derived from people aged 65 years and above. All other estimates derived from people aged 70 years and above