FIG 4.

Discordant detection of S. aureus and H. influenzae by bacterial quantity (left) and specimen type (right). Multivariate, least-squares, linear regression demonstrates that S. aureus (a and b) and H. influenzae (c and d) quantity as measured by BFPP was directly and independently associated with concordant detection by BFPP and SOC culture, compared to detection by BFPP alone (S. aureus model, r-squared = 0.35 and df = 37; H. influenzae model, r-squared = 0.57 and df = 21). P values from regression coefficients are represented as follows: ***, P < 0.001; **, P < 0.01; *, P < 0.05; and ns, nonsignificant. Values inside columns represent the number of samples per horizontal-axis category as grouped by test concordance.