Fan 2017.
Methods | 2‐arm, parallel group, randomised, controlled trial, 6 months duration. | |
Participants |
Location: China, Shandong (Weifang), single centre. Setting of recruitment and treatment: community. Sample size
Participant baseline characteristics:
Inclusion criteria:
Exclusion criteria:
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Interventions |
Intervention: 400 µg folic acid per day orally for 6 months. Comparator group: No intervention, maintenance of their usual lifestyle and eating habits. Use of additional interventions (common to both treatment arm): not reported. |
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Outcomes | Overall cognitive function: MMSE (also measured: MoCA). Functional performance: Activities of Daily Living (ADL) scale. |
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Source of Funding | Not reported. | |
Declaration of Interest | No declarations. | |
Notes | ||
Risk of bias | ||
Bias | Authors' judgement | Support for judgement |
Random sequence generation (selection bias) | Low risk | Random number table “按随机数字表法将受试对象随机分为对照组和干预组,每组40例。” (page 4161) |
Allocation concealment (selection bias) | Unclear risk | No information |
Blinding of participants and personnel (performance bias) All outcomes | High risk | Not blinded. On the first day of each month, subjects in the experimental group were given a bottle of folic acid (400μg/tablet, 30 tablets/bottle) by research staff in community. They were instructed to take one tablet per day. Research staff contacted participants regularly and recorded the usage of folic acid in the intervention group. No mention of contact with comparator group. “干预组每月第1天由社区服务站相关人员统一发放规格为每片400μg的叶酸1瓶(30片),每天服用1片,持续6个月,定期回访,询问叶酸服用情况并记录。” “对照组不进行任何干预,维持原有的生活、饮食习惯。” (page 4161) |
Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | No information |
Incomplete outcome data (attrition bias) All outcomes | Low risk | 75/80 (94%) completed trial. 3 dropped out in control arm, and 2 dropped out in intervention arm. 2 cases excluded for missing more than 5 doses, 3 cases voluntary dropout, group allocations not reported. Results reported only for the 75 participants who completed the trial. |
Selective reporting (reporting bias) | Low risk | Results were reported for all outcomes mentioned in the Methods section of paper. No protocol identified. |
Other bias | Low risk | No other sources of bias identified. |