Skip to main content

Table 3 Adjusted effects of mosquito-disseminated pyriproxyfen on species-specific adult-mosquito catches (Aedes aegypti and Culex quinquefasciatus): top-ranking (smallest-BIC) generalized linear mixed models

From: Measuring mosquito control: adult-mosquito catches vs egg-trap data as endpoints of a cluster-randomized controlled trial of mosquito-disseminated pyriproxyfen

Term

Estimate

SE

95% CI

Lower

Upper

Aedes aegypti

Fixed effects

Intercept (CC, BP)a

− 0.618

0.354

− 1.312

0.077

Intervention period (IP)b

− 0.535

0.367

− 1.253

0.184

Intervention cluster (IC)

0.508

0.319

− 0.118

1.134

IP × ICc

− 0.916

0.295

− 1.493

− 0.338

Rainfalld

0.829

0.146

0.543

1.116

Random effects SD

Dwelling ID

0.766

–

0.585

1.001

Month

0.455

–

0.275

0.755

Culex quinquefasciatus

Fixed effects

Intercept (CC, BP)a

0.430

0.396

− 0.346

1.205

Intervention period (IP)b

0.080

0.382

− 0.669

0.828

Intervention cluster (IC)

− 1.172

0.380

− 1.917

− 0.427

IP × ICc

− 0.807

0.291

− 1.378

− 0.237

Temperatured

0.707

0.156

0.400

1.012

Random effects SD

Dwelling ID

1.091

–

0.868

1.370

Month

0.502

–

0.328

0.767

  1. aThe intercept estimates the (log-scale) expected mean number of mosquitoes caught per 10 minutes aspiration in the CC, in the typical dwelling and at typical temperatures, during the BP; the other fixed-effect slope coefficients estimate changes in this expectation associated with period, cluster, intervention, and rainfall or temperature effects
  2. bNote that both models estimate non-significant changes in (log) mean mosquito-catch as the CC entered the IP (but received no intervention), with the 95% confidence intervals including zero
  3. cThe ‘IP × IC’ interaction coefficients estimate the (log) change in expected mean mosquito-catch that can be attributed to the intervention (deployment of 150 pyriproxyfen dissemination stations over 13 months (the IP) in the IC). The Aedes model estimates an e− 0.916 = 0.400 incidence rate ratio, indicating that the intervention resulted in a 100 − 40.0 = 60.0% reduction (95% CI: 28.7–77.5%) of the expected mean Aedes-catch; the Culex model estimates an e− 0.807 = 0.446 incidence rate ratio, or a 55.4% reduction (95% CI: 21.1–74.8%) of the expected mean Culex catch
  4. dSpecified as the (standardized) total rainfall in the month before sampling (‘rain_m’) for the Aedes model and as the mean of minimum daily temperatures in the month before sampling (‘tmin_m’) for the Culex model; the original variables had the following means (SDs): ‘rain_m’, 131.6 mm (111.3); ‘tmin_m’, 17.39°C (1.73). Given our focus on estimating adjusted intervention effects, we considered weather covariates as confounders; those in the table yielded better-performing models, as measured by BIC scores, than other measures of temperature and rainfall
  5. Abbreviations: BIC, Bayesian information criterion; SE, standard error; 95% CI, 95% confidence interval (lower/upper limits); CC, control cluster; BP, baseline period; IP, intervention period; IC, intervention cluster; SD, standard deviation; ID, identity of each sampling dwelling
Back to article page

Parasites & Vectors

ISSN: 1756-3305

Contact us