Table 2.
Risk factors that are common in non-communicable neurological disorders (i.e., found in more than one disease under consideration)
| Factor | Metric | Effect size (95% CI) | Neurological condition | Level of evidence | Study |
|---|---|---|---|---|---|
| Farming | OR | 1.42 (1.17–1.73) | Amyotrophic lateral sclerosis | Suggestive | Belbasis, 2016 [78] |
| OR | 1.30 (1.16–1.46) | Parkinson disease | III | Bellou, 2016 [50] | |
| Pesticides | OR | 1.62 (1.40–1.88) | Parkinson disease | III | Bellou, 2016 [50] |
| OR | 1.44 (1.22–1.70) | Amyotrophic lateral sclerosis | Weak | Belbasis, 2016 [78] | |
| Type 2 diabetes mellitus | RR | 1.54 (1.39–1.72) | Alzheimer disease | Convincing | Bellou, 2017 [49] |
| RR | 1.60 (1.43–1.79) | Dementia | Highly suggestive | Bellou, 2017 [49] | |
| RR | 2.28 (1.94–2.66) | Vascular dementia | Convincing | Bellou, 2017 [49] | |
| Low-frequency electromagnetic fields | OR | 1.29 (1.03–1.62) | Amyotrophic lateral sclerosis | Weak | Belbasis, 2016 [78] |
| RR | 1.74 (1.37–2.21) | Alzheimer disease | Suggestive | Bellou, 2017 [49] | |
| Organic solvents | OR | 1.54 (1.03–2.29) | Multiple sclerosis | Weak | Belbasis, 2016 [78] |
| OR | 1.22 (1.01–1.47) | Parkinson disease | IV | Bellou, 2016 [50] | |
| Midlife BMI | RR | 1.81 (1.22–2.69) | Alzheimer disease | Weak | Bellou, 2016 [50] |
| RR | 1.91 (1.40–2.62) | Dementia | Suggestive | Bellou, 2017 [49] | |
| Head injury | OR | 1.65 (1.09–2.51) | Amyotrophic lateral sclerosis | Suggestive | Belbasis, 2016 [78] |
| OR | 1.55 (1.33–1.81) | Parkinson disease | II | Bellou, 2016 [50] | |
| Mild traumatic brain injury | OR | 1.35 (1.01–1.78) | Dementia | Weak | Bellou, 2017 [49] |
| OR | 1.40 (1.03–1.90) | Alzheimer disease | Weak | Bellou, 2017 [49] | |
| Depression at any age/stage | RR | 1.99 (1.84–2.16) | Dementia | Convincing | Bellou, 2017 [49] |
| RR | 2.92 (1.87–4.56) | Vascular dementia | Weak | Bellou, 2017 [49] | |
| RR | 1.77 (1.48–2.13) | Alzheimer disease | Highly suggestive | Bellou, 2017 [49] | |
| Late-life depression | RR | 1.85 (1.67–2.05) | Dementia | Convincing | Bellou, 2017 [49] |
| OR | 2.52 (1.77–3.59) | Vascular dementia | Weak | Bellou, 2017 [49] | |
| RR | 1.65 (1.42–1.92) | Alzheimer disease | Convincing | Bellou, 2017 [49] | |
| Low level of Education | RR | 1.88 (1.51–2.33) | Dementia | Suggestive | Bellou, 2017 [49] |
| RR | 2.75 (2.19–3.45) | Vascular dementia | Weak | Bellou, 2017 [49] | |
| RR | 1.82 (1.36–2.43) | Alzheimer disease | Suggestive | Bellou, 2017 [49] |
Abbreviations: BMI body mass index, OR odds ratio, RR relative risk, 95% CI 95% confidence interval
Note: In this table, only statistically significant risk factors that appeared in more than two studies were included