Balfour 1936 GRC

Methods	Trial design: Controlled before‐and‐after trial Type of cluster: Town and rural areas Cluster size: Population of towns: 1700; 1130; 830; 32,200; 31,550 individuals Number of clusters in each arm: Intervention arm: two; control arm: three Adjusted for clustering? No
Participants	Age: School children Sex: Any Co‐morbidities and pregnancy: Any Primary outcome sample size (Parasite prevalence): 210, 112, 97, 853, 650 participants per survey Secondary outcome sample size (Splenomegaly prevalence): 210, 112, 97, 853, 650 participants per survey
Interventions	Intervention: Habitat modification with larviciding Details of the intervention:                                            Habitat modification: Drainage and reclamation of marshland, straightening of rivers and construction of embankments                                                     Larviciding: Larval habitats were treated with Paris Green (dosage not stated) Frequency of application: Not stated Duration of intervention period: 60 months Who was responsible for LSM? The government Co‐interventions: Case management: treatment with quinine (coverage not stated) Co‐interventions equal in each arm? Not stated
Outcomes	1. Parasite prevalence (measured with yearly cross‐sectional surveys) 2. Splenomegaly prevalence (measured with yearly cross‐sectional surveys)
Notes	Continent: Europe Country: Greece Ecosystem: Coastal Urban or rural: Urban and rural Extensive or localized larval habitats: Localized Primary larval habitats: Primarily man‐made habitats Transmission intensity: Low to moderate Transmission season(s): May to October Primary and secondary vector:An. elutus, An. superpictus Primary malaria parasite:P. falciparum, P. vivax Source of funding: Not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Not randomly chosen.
Allocation concealment (selection bias)	High risk	Not randomly chosen.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Impossible to blind evaluators to intervention.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Impossible to blind implementers to intervention.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Reporting ceased from one clinic. Individual patients not followed up therefore not possible to measure percentage loss to follow‐up.
Selective reporting (reporting bias)	Low risk	Outcome reporting complete.
Baseline characteristics	Low risk	Baseline characteristics reported.
Contamination	Unclear risk	Not stated how far apart the towns were.
Incorrect analysis	Unclear risk	Cluster adjustment not applicable.
Other bias	High risk	High risk of confounding.