Table 5.

Summary estimates, 95% CIs and data descriptions for household SHS exposure comparisons grouped by type of asthma.^a

			Asthma type		Percentile
Type of combined estimate of RRb	No.	RR	95% CI	p-Value	Min	25th	75th	Max
Current
Uncorrected	15	1.30	1.22–1.39	0.249*	0.86	1.24	1.60	2.17
Correctedc	11	1.25	1.21–1.30	0.528	0.88	1.23	1.38	2.17
Ever
All studiesc,d	23	1.48	1.32–1.65	<0.001*	0.57	1.45	1.74	5.81
Household SHS	17	1.51	1.31–1.75	<0.001*	0.94	1.47	1.73	5.81
Maternal smoking	6	1.29	1.15–1.45	0.190*	1.21	1.21	1.98	2.77
Incident
All studies	8	1.21	1.08–1.36	0.225*	0.84	1.08	1.33	1.49
Household SHS	4	1.13	0.89–1.44	0.544	0.84	0.92	1.26	1.27
Maternal smoking	4	1.24	1.06–1.45	0.074*	1.08	1.08	1.45	1.49

Abbreviations: CI, confidence interval; Max, maximum value of the distribution; Min, minimum value of the distribution; p-value, value from the p distribution for the null hypothesis that the rate ratio is constant across studies.

^aWe report random effects estimates.

^bWe report corrected estimates unless otherwise indicated.

^cWe removed four studies from the analysis of current asthma (Azizi et al. 1995; Daigler et al. 1991; Murray and Morrison 1990; Palmieri et al. 1990) and one study from the analysis of ever asthma (Pokharel et al. 2001) for lack of enough information to convert odds ratios into estimates of RR.

^dExcluded six studies already included in the current asthma analysis.

^*Heterogeneity.