Table 2.

Distribution of RSV positive bronchiolitis episodes among all infants (≤12 months), those ≤6‐months, and those ≤3‐months of age, and by type of healthcare encounter at age ≤ 6‐months in the PRIMA‐KPNC study cohort, 2006–2009

Month	ICD‐9 codes captured episodes	By age range						By encounter type at age ≤ 6‐months
		≤12 months		≤6‐months		≤3‐months		OPV		EDV		Hospitalization
		n	%+	n	%+	n	%+	n	% +	n	%+	n	%+
Dec	1,252	470	60.0	246	65.0	86	70.9	194	60.8	3	100	49	79.6
Jan	2,854	781	65.8	405	69.4	237	67.5	291	64.9	12	83.3	102	80.4
Feb	2,663	542	58.5	283	59.4	223	60.5	207	55.6	8	62.5	68	70.6
Total	6,769	1,793	62.0	934	65.2	546	65.2	692	60.9	23	78.3	219	77.2

n = number tested, which is denominator for % RSV positive (%+). Note: the number does not add up to the total sample size because only three peak months are included in the table (please see Table S2 for full year results).