Haushofer 2013.
Study characteristics | ||
Methods |
Study design: RCT Study grouping: parallel How were missing data handled? missing data due to attrition excluded from analysis. Analyses were based on total 1372 HHs, which is the sum of HHs at baseline only. Randomisation ratio: 1:1 (503:505) Recruitment method: after HHs and members identified, in private conversation, members were asked questions about demographics, and informed that they had been chosen to receive a cash transfer of KES 25,200 (USD 404). The recipient was informed that this transfer was unconditional, that they were free to spend it however they chose, and that it was a one‐time transfer and would not be repeated. Sample size justification and outcome used: sample size 500 individuals in each of the treatment, control and pure control group was chosen based on a power calculation, which showed that a sample of 1000 individuals was sufficient to detect effect sizes of 0.2 SD for all treatment vs pure control HHs with 89% power. Different treatment groups within the treatment groups (male vs female recipient, lump‐sum vs monthly, large vs small transfers) could be compared with 60% power (from registry record). Sampling method: purposive sampling of villages and HHs followed by random selection of HHs into treatment or control groups. GiveDirectly selected poor HHs by identifying poor regions of Kenya according to census data. Region chosen was Rarieda, a peninsula in Lake Victoria west of Kisumu in Western Kenya. GiveDirectly identified target villages through a rough estimation of the population of villages and the proportion of HHs lacking a metal roof, which is GiveDirectly's targeting criterion. Identified 126 villages. 63 of these villages were randomly chosen to be treatment villages. Control villages were only surveyed at endline; in these villages, authors sampled 432 HHs referred to as 'pure control' HHs. In treatment villages, second stage of randomisation assigned 50% of HHs to treatment condition, and 50% to control condition. Process resulted in 503 treatment HHs and 505 control HHs in treatment villages at baseline. Note: numbers were different between reports. Study aim or objective: to assess the relative welfare impacts of 3 design features of UCTs: gender of transfer recipient; temporal structure of transfers (monthly vs lump‐sum); and magnitude of transfer. Study period: transfers between June 2011 and January 2013 Unit of allocation or exposure: HHs |
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Participants |
Baseline characteristics Intervention or exposure
Control
Overall: NR Inclusion criteria: HHs lacking metal roof (indicator of poverty) Exclusion criteria: none reported Pretreatment: results were largely insignificant, suggesting that the treatment and control groups did not differ at baseline. Attrition per relevant group: overall: 68 (6.7%) (940/1008 surveyed at endline). Treatment: 32 (6.4%); LTFU (471/503 surveyed at endline); control: 36 (7.1%); LTFU (469/505 surveyed at endline) Description of subgroups measured and reported: male vs female recipients of transfers; monthly vs lump‐sum transfers; large vs small transfers Total number completed and analysed per relevant group: treatment: 471 HHs; control: 469 HHs Total number enrolled per relevant group: treatment: 503 HHs; control: 505 HHs Total number randomised per relevant group: treatment: 503 HHs; control: 505 HHs |
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Interventions |
Intervention characteristics Intervention or exposure
Control: no intervention |
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Outcomes | Proportion of HH expenditure on food: Total monthly HH food expenditure (cereals, tubers, meat/fish, dairy, fruit/vegetables, other food, food eaten out, Food security: FSI (based on weighted mean of measures of food security and hunger based on 17 outcome measures) Anthropometry: MUAC; height; weight Anxiety and depression: psychological well‐being index (standardised weighted mean of 6 psychological and neurobiological measures); log cortisol; CES‐D; Cohen PSS |
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Identification |
Sponsorship source: NIH Grant R01AG039297 and Cogito Foundation Grant R‐116/10 to Johannes Haushofer. Country: Kenya Setting: poor rural villages in Kenya Comments: additional documentation: online Appendix. RCT ID (trial registry): AEARCTR‐0000019 (www.socialscienceregistry.org/trials/19) Author's name: Johannes Haushofer Email: joha@mit.edu Declarations of interest: NR either authors. Quote: "Shapiro is a co‐founder and former director of GiveDirectly, Inc. (2009–2012). This paper does not necessarily represent the views of GiveDirectly, Inc" Study or programme name and acronym: N/A Type of record: report |
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Notes | ||
Risk of bias | ||
Bias | Authors' judgement | Support for judgement |
Random sequence generation (Selection bias) | Unclear risk | Randomisation method NR. |
Allocation concealment (Selection bias) | Unclear risk | Concealment of allocation was not described, and HHs in the same cluster (village) were randomised to either receive the intervention or not. |
Baseline characteristics similar (Selection bias) | Low risk | Quote: "The only significant difference between treatment and control households appears in income from self‐employment, where treatment households have a $33 PPP [purchasing power parity] lower income relative to the control mean of $85 PPP (39%) at baseline. This difference is significant at the 10% level, but does not survive FWER [familywise error rate] correction for multiple inference" |
Baseline outcome measurements similar (Selection bias) | Low risk | Quote: "Online Appendix Table 35 shows only minor differences in the estimates of the treatment effects when baseline controls are included; none of the significant results become non significant or vice versa. Thus, baseline covariates do not affect our results strongly." "The only significant difference between treatment and control households appears in income from self‐employment, where treatment household shave a $33 PPP lower income relative to the control mean of $85 PPP (39%) at baseline. This difference is significant at the 10% level, but does not survive FWER correction for multiple inference." |
Blinding of participants and personnel (Performance bias) | Low risk | No blinding. Unlikely to influence behaviour or experience of participants. |
Blinding of outcome assessment (Detection bias) | High risk | No blinding, which may have affected self‐reported outcomes of participants who did not receive the cash transfers. |
Protection against contamination (Performance bias) | Low risk | Quote: "First, we find no spillovers in consumption. This is surprising, given that we might have expected some informal insurance among households: in effect, the transfer is a temporary lottery gain, and theory predicts that households should have been sharing it with their insurance network." |
Incomplete outcome data (Attrition bias) | Low risk | Few and balanced missing data – approximately 6% in each group. This was unlikely to introduce bias. |
Selective outcome reporting (Reporting bias) | Low risk | No study protocol available but all outcomes outlined in registry were reported. |
Other bias | Unclear risk | Misclassification bias: low. Measurement bias: unclear. Potential bias as information on dietary intake only captured at baseline and after 1 year. Incorrect analysis: unclear. Although there was a cluster randomisation, the analysis used for this review were at HH level and not cluster level. Comparison of intervention and control HHs in villages allocated to intervention group. |