General characteristics of included amyotrophic lateral sclerosis (ALS) patients.
| Study | ALS/control | Nation | Gender ratio (M:F) | Age at sample (mean) | %Bulbar onset | BMI (kg/m2) | ALSFRS (/48) (mean) | %FVC (mean) | Quality scores | Ferritin assay (/30) |
|---|---|---|---|---|---|---|---|---|---|---|
| Goodall et al 200811 | 60/44 | UK | 2.16 | 60.0 | NR | NR | NR | NR | 26 | NR |
| Qureshi et al 200812 | 30/30 | USA | 1.31 | NR | NR | NR | NR | NR | 29 | NR |
| Nadjar et al 201214 | 629/297 | France | 1.05 | 61.5 | 34.1 | NR | 30.62 | NR | 29 | NIA |
| Ikeda et al 201213 | 92/92 | Japan | 1.63 | 58.8 | 10.9 | 22.6 | 40.30 | 94.3 | 29 | EIA |
| Veyrat-Durebex et al 201415 | 104/145 | France | 1.08 | 67.6 | 40.8 | NR | 37.00 | 82.0 | 29 | EIA |
| Su et al 201516 | 138/152 | USA | 1.71 | 62.1 | 35.5 | NR | NR | NR | 28 | EIA |
| Total | 1053/760 | 1.40 | 61.9 | 32.8 | 22.6 | 32.50 | 87.8 |
M:F - the ratio of males to females for included ALS patient, %Bulbar onset - the percentage of bulbar onset defined as symptoms first occurring at the bulbar level with dysphagia, dysphonia, or dysarthria, BMI - body mass index, ALSFRS - ALS functional rating scale, FVC - forced vital capacity,
NR - not reported, NIA - nephelometric immunoassay, EIA electrochemiluminescence immunoassay, quality scores were assigned using the Downs and Black quality assessment scale (DBQAS)