Incidence and comparison of retrospective and prospective data on respiratory and gastrointestinal infections in German households

Table 2 Incidence of acute respiratory (ARI) and gastrointestinal (AGI) infections, by mode of data collection and age group

		Prospective data collection				Retrospective data collection				Significance (p-value for differences between the study arms
		Person days	Episodes	Incidence per person month (30 days)^c	Incidence per person year (365 days)	Person days	Episodes	Incidence per person month (30 days)^c	Incidence per person year (365 days)	α = 0.05
ARI	Age groups
	0–3 years	7009	164	0.7 (0.59; 0.82)	8.54	8311	217	0.78 (0.68; 0.89)	9.49	p = 0.31
	4–6 years	5729	100	0.52 (0.43; 0.64)	6.37	5882	103	0.53 (0.43; 0.64)	6.39	p = 1.00
	7–15 years	1891	13	0.21 (0.12; 0.33)	2.51	2828	41	0.43 (0.31; 0.59)	5.29	p = 0.02
	> 15 years	17,274	229	0.4 (0.35; 0.45)	4.84	22,970	330	0.43 (0.39; 0.48)	5.22	p = 0.37
	Total	32387^a	507	0.47 (0.42; 0.52)	5.71	40050^b	691	0.52 (0.48; 0.56)	6.32	p = 0.10
AGI	Age groups
	0–3 years	7117	48	0.2 (0.16; 0.26)	2.46	8120	53	0.2 (0.15; 0.26)	2.37	p = 0.95
	4–6 years	5792	24	0.12 (0.08; 0.18)	1.51	5721	30	0.16 (0.11; 0.22)	1.91	p = 0.47
	7–15 years	1902	6	0.09 (0.04; 0.20)	1.15	2724	17	0.19 (0.11; 0.30)	2.28	p = 0.21
	> 15 years	17,441	66	0.11 (0.09; 0.15)	1.38	22,370	83	0.11 (0.09; 0.14)	1.35	p = 0.97
	Total	32736^a	144	0.13 (0.11; 0.16)	1.61	38994^b	183	0.14 (0.12; 0.16)	1.7	p = 0.60

^aMissing information on age for 4 persons (contributing 484 person days), ^bMissing information on age for 1 person (contributing 59 person days), ^cConfidence Intervals (CI’s) in brackets

ISSN: 1471-2334