Table 3.
Subgroup analyses (serum LDL-C levels and PD risk).
| Variables | No. of studies | Test of association | Test of heterogeneity | ||
|---|---|---|---|---|---|
| Pooled RR (95%CI) | P value | I2 (%) | P value | ||
| Study location | |||||
| Europe | 3 | 0.82 (0.64–1.04) | 0.099 | 50.3 | 0.134 |
| Americas | 1 | 0.43 (0.21–0.88) | 0.021 | — | — |
| Asia | 1 | 0.60 (0.40–1.10) | 0.099 | — | — |
| Statin adjustment/excluding statin users | |||||
| YES | 3 | 0.66 (0.49–0.90) | 0.006 | 35.3 | 0.213 |
| NO | 2 | 0.81 (0.50–1.31) | 0.085 | 66.9 | 0.082 |
| Gender | |||||
| Male | 2 | 0.69 (0.54–0.88) | 0.003 | 0 | 0.537 |
| Female | 1 | 0.88 (0.62–1.29) | 0.494 | — | — |
RR, relative risk; CI, confidence interval; NOS, Newcastle-Ottawa Scale; PD, Parkinson's disease; LDL-C, low-density lipoprotein cholesterol. P value for heterogeneity within subgroup.