Table 1.
Virtual antenatal intervention for improved diet and iron intake (VALID) trial outcome measures.
| VALID trial outcomes | Recorded also at baselineb |
Recall period |
Definition | Variable type |
Effect measure to compare arms |
|---|---|---|---|---|---|
| Primary outcome | |||||
| Compliance with recommended iron and folic acid tablet (IFA) intake | Yes | 14 days | IFA consumed on 12 or more days out of the previous 14 days (i.e., on at least 80% of days) | Binary | Odds ratio and difference in proportiona |
| Secondary outcomes | |||||
| Dietary diversity | Yes | 24 h | Count of the number of food groups consumed in the previous 24 h preceding the endline interview, assessed using the list-based method, out of 10 food groups | Count (0–10) | Difference in mean |
| Consumption of intervention-promoted foods | Yes | 24 h | Any consumption of green leafy vegetables, meat, or fish | Binary | Odds ratio and difference in proportiona |
| Practicing one or more methods to enhance bioavailability | Yes | 7 days | Recalled one or more of the following: using lemon or other vitamin C-rich foods with meals, eating sprouted grains or pulses, avoiding tea/coffee 1 h on either side of meals, or spreading meat-eating over two eating occasions rather than one | Binary | Odds ratio and difference in proportiona |
| Knowledge of iron-rich foods | No | N/A | Count of iron-rich food groups correctly recalled | Count (0–9) | Difference in mean |
| ANC visits | No | Baseline to endline | Antenatal care (ANC) visits between enrolment and endline interview | Count (0–4) | Difference in mean |
| Exploratory outcomes | |||||
| Understanding of why blood tests are taken at antenatal check-ups. | Yes | N/A | The proportion of those women who had a blood test at ANC who could correctly explain one or more reasons for having a blood test | Binary | Odds ratio and difference in proportiona |
| Knowledge of COVID-19 symptoms, precautions, and vulnerability | No | N/A | The proportion of women who could correctly identify at least one vulnerable group, at least three coronavirus disease 2019 (COVID-19) control/prevention measures, and at least three COVID-19 symptoms | Binary | Odds ratio and difference in proportiona |
| ANC visits at the right time for her gestational age | Yes | Pregnancy to date | Whether the woman had her ANC visits at 2, 4, 6, and 8 months or not | Binary | % by arm (no effect measure) |
a
Formal testing is linked to the odds ratio, but the effect is also expressed as a difference in proportion.
b
Items recorded at baseline are adjusted for in analyses.