Table 3. Potential prespecified sources of heterogeneity explored among the studies reporting an association between psoriasis and obesity.

Prespecified source of heterogeneity	Number of estimates	Stratified fixed-effects meta-analysis OR (95% CI)	Meta-regression P-value for heterogeneity
Study location			0.78
USA	1	2.39 (1.98–2.90)
Europe	8	1.56 (1.31–1.86)
Other	7	1.69 (1.39–2.06)
Source population			0.09
Inpatient	2	1.12 (0.89–1.41)
Outpatient	14	1.75 (1.54–1.99)
Statistical adjustment			0.004
Not adjusted	6	2.32 (1.79–3.01)
Adjusted	10	1.41 (1.26–1.58)
Study quality			0.13
Lower (0–3)	6	2.19 (1.70–2.81)
Higher (4–6)	11	1.48 (1.30–1.68)
Outcome ascertainment			0.86
Billing data	1	1.72 (1.68–1.76)
Chart review	11	1.66 (1.44–1.91)
Examination	4	1.66 (0.97–2.83)
Analysis of outcome			0.42
Primary	11	1.75 (1.49–2.06)
Secondary	5	1.48 (1.24–1.77)
Severity of psoriasis			0.55
No distinction	10	1.62 (1.32–1.97)
Mild vs severe	6	1.74 (1.43–2.12)

Abbreviations: CI, confidence interval; OR, odds ratio.