Table 3.
Variables that are both risk and protective factors for non-communicable neurological disorders
| Factor | Effect size metric | Effect size (95% CI) | Neurological condition | Level of evidence | Study |
|---|---|---|---|---|---|
| Smoking | RR | 1.26 (1.05–1.50) | Vascular dementia | Weak | Bellou, 2017 [49] |
| OR | 1.52 (1.39–1.66) | Multiple sclerosis | Convincing | Belbasis, 2015 [18, 51] | |
| RR | 0.64 (0.60–0.69) | Parkinson disease | II | Bellou, 2016 [50] | |
| RR | 1.13 (1.05–1.22) | Dementia | Weak | Bellou, 2017 [49] | |
| Hypertension | HR | 1.59 (1.20–2.11) | Vascular dementia | Weak | Bellou, 2017 [49] |
| RR | 0.75 (0.61–0.90) | Parkinson disease | IV | Bellou, 2016 [50] | |
| Serum uric acid | SMD to RR | 0.58 (0.41–0.83) | Dementia | IV | Li, 2017 [86] |
| SMD to RR | 0.49 (0.27–0.87) | Multiple sclerosis | IV | Li, 2017 [86] | |
| RR | 2.83 (2.13–3.76) | Diabetic peripheral neuropathy | IV | Li, 2017 [86] | |
| aRR | 1.32 (1.23–1.41) | Stroke mortality | I | Li, 2017 [86] | |
| MD to OR | 0.29 (0.11–0.76) | Alzheimer disease | IV | Li, 2017 [86] | |
| RR | 0.65 (0.43–0.97) | Parkinson disease incidence | IV | Li, 2017 [86] | |
| OR | 0.28 (0.14–0.57) | Multiple sclerosis | Weak | Belbasis, 2015 [18, 51] | |
| SMD to RR | 0.22 (0.10–0.45) | Neuromyelitis optica | IV | Li, 2017 [86] | |
| Hedge’s to RR | 0.21 (0.14–0.32) | Amyotrophic lateral sclerosis | IV | Li, 2017 [86] | |
| OR | 0.39 (0.27–0.57) | Parkinson disease | II | Bellou, 2016 [50] |
Abbreviations: N/A not available, OR odds ratio, RR relative risk, HR hazard ratio, SMD standardized mean difference, aRR adjusted relative risk, MD mean difference, 95% CI 95% confidence interval