Table 3. Stratified effect estimates of metabolic syndrome for COPD risk.
| Stratified groups | Number | OR | 95% CI | P | I2 | PQ-test |
|---|---|---|---|---|---|---|
| COPD diagnosis | ||||||
| GOLD | 18 | 1.48 | 1.20–1.84 | <0.001 | 75.4% | <0.001 |
| ATS (1987) | 2 | 3.14 | 0.70–14.09 | 0.134 | 46.9% | 0.170 |
| By MetS | ||||||
| ATP-III | 12 | 1.72 | 1.24–2.4 | 0.001 | 83.6% | <0.001 |
| IDF | 8 | 1.39 | 1.03–1.88 | 0.032 | 49.1% | 0.056 |
| JIS (2009) | 2 | 1.18 | 0.79–1.77 | 0.41 | 0.0% | 0.802 |
| By gender | ||||||
| Males | 5 | 1.22 | 0.78–1.91 | 0.384 | 84.8% | <0.001 |
| Females | 4 | 1.28 | 1.08–1.53 | 0.004 | 0.0% | 0.414 |
| By study design | ||||||
| Cross-sectional | 11 | 1.67 | 1.09–2.58 | 0.02 | 83.2% | <0.001 |
| Nested | 9 | 1.35 | 1.14–1.6 | <0.001 | 34.5% | 0.142 |
| By source of controls | ||||||
| Hospital | 8 | 2.43 | 1.41–4.18 | 0.001 | 33.7% | 0.159 |
| Population | 12 | 1.38 | 1.1–1.73 | 0.006 | 80.6% | <0.001 |
| By race | ||||||
| Asian | 9 | 1.24 | 0.97–1.59 | 0.085 | 74.2% | <0.001 |
| Caucasian | 7 | 2.05 | 1.7–2.46 | <0.001 | 0.0% | 0.445 |
| Middle Eastern | 3 | 2.83 | 1.65–4.86 | <0.001 | 0.0% | 0.440 |
| Mixed | 1 | 1.17 | 0.77–1.77 | 0.46 | NA | |
| By country development | ||||||
| Developed | 13 | 1.44 | 1.09–1.9 | 0.01 | 80.0% | <0.001 |
| Developing | 7 | 1.76 | 1.19–2.6 | 0.004 | 57.5% | 0.028 |
| By matched status | ||||||
| NR | 11 | 1.23 | 1.0–1.52 | 0.051 | 69.7% | <0.001 |
| Yes | 9 | 2.21 | 1.83–2.68 | <0.001 | 0.0% | 0.460 |
| By total sample size | ||||||
| <300 | 10 | 2.16 | 1.47–3.16 | <0.001 | 19.6% | 0.262 |
| ≥300 | 10 | 1.34 | 1.05–1.71 | 0.02 | 83.8% | <0.001 |
Abbreviations: 95% CI, 95% confidence interval; ATP-III, the Adult Treatment Panel III; COPD, chronic obstructive pulmonary disease; IDF, International Diabetes Federation; JIS (2009), a joint interim statement in 2009 (Circulation 2009; 120:1640–1645); MetS, metabolic syndrome; NA, not reported; OR, odds ratio. The term ‘Number’ in the first row referred to the number of eligible studies.