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Table 2 Adjusted effects of mosquito-disseminated pyriproxyfen on adult-mosquito catches (Aedes aegypti + Culex quinquefasciatus): top-ranking (smallest-BIC) generalized linear mixed model

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

Fixed effects

Intercept (CC, BP)a

0.776

0.352

0.087

1.465

Intervention period (IP)b

0.028

0.341

− 0.641

0.697

Intervention cluster (IC)

− 0.436

0.317

− 1.056

0.185

IP × ICc

− 1.086

0.227

− 1.532

− 0.641

Temperatured

0.721

0.139

0.448

0.994

Random effects SD

Dwelling ID

0.956

–

0.773

1.183

Month

0.456

–

0.303

0.686

  1. aThe intercept estimates the (log-scale) expected mean number of mosquitoes caught per 10 min 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 temperature effects
  2. bNote that the model estimates a near-zero change in (log) mean mosquito-catch as the CC entered the IP (but received no intervention); the estimated incidence rate ratio is e0.028 = 1.028, or a 2.8% increase in mean mosquito-catch, with the 95% CI spanning zero
  3. cThe ‘IP × IC’ interaction coefficient estimates 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 intervention period ‘IP’) in the intervention cluster ‘IC’. Here, the model estimates an e− 1.086 = 0.337 incidence rate ratio, indicating that the intervention resulted in a 100 −  33.7 = 66.3% reduction (95% CI: 47.3–78.4%) of the expected mean mosquito-catch
  4. dSpecified as the (standardized) mean of minimum daily temperatures in the month before each sampling occasion (‘tmin_m’); the original variable had mean = 17.39°C and SD = 1.73°C. Given our focus on estimating adjusted intervention effects, we considered weather covariates as confounders; ‘tmin_m’ 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
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Parasites & Vectors

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