ObjectiveTo study the effectiveness of amblyopia screening at ages 3–4.Methods and AnalysisFrom a population with no previous screening, a cohort of 2300 children with 3–4 years old attending school (91% of children this age attend school in Portugal), were submitted to a complete ophthalmological evaluation. Amblyopia was diagnosed, treated and followed. Amblyopia prevalence, treatment effectiveness, absolute risk reduction (ARR), number needed to screen (NNS) and relative risk reduction (RRR) were estimated.ResultsPast/present history of amblyopia was higher than 3.1%–4.2%, depending on amblyopia definition normatives. Screening at age 3–4, had estimated ARR=2.09% (95% CI 1.50% to 2.68%) with a reduced risk of amblyopia in adulthood of 87% (RRR). NNS was 47.8 (95% CI 37.3 to 66.7). Treatment effectiveness of new diagnosis was 88% (83% if we include children already followed). 91% of new amblyopia diagnoses were refractive (of which 100% surpassed amblyopia Multi-Ethnic Pediatric Eye Disease Study criteria after treatment), while most strabismic amblyopias were already treated or undertreatment. Only 30% of children with refractive amblyopia risk factors that were not followed by an ophthalmologist, ended up having amblyopia at age 3–4. Eye patch was needed equally in new-diagnosis versus treated-earlier refractive amblyopia.ConclusionsScreening amblyopia in a whole-population setting at age 3–4 is highly effective. For each 48 children screened at age 3–4, one amblyopia is estimated to be prevented in the future (NNS). Screening earlier may lead to overdiagnosis and overtreatments: Treating all new diagnosis before age 3–4 would have a maximal difference in ARR of 0.3%, with the possible burden of as much as 70% children being unnecessary treated before age 3–4.Involving primary care, with policies for timely referral of suspicious/high-risk preverbal children, plus whole screening at age 3–4 seems a rational/effective way of controlling amblyopia.

Objectives: to describe the characteristics of pneumonia hospitalizations in children under five years of age across the State of Maranhão, Brazil, and explore patterns of spatial distribution of admissions. Methods: ecological study using data on occurrences (age, gender, skin color/race, month of occurrence, and municipality of residence) between 2012 and 2017 taken from the Unified Health System’s Hospital Information System and municipal level socioeconomic indicators for 2010. Each respiratory disease, including pneumonia, was presented as a percentage of overall admissions for respiratory tract diseases, together with the monthly distribution of admissions as a percentage of total annual cases, and annual rate of admissions by gender. The General G* statistic was calculated to identify significant clustering of municipalities with similar proportions of hospital admissions for pneumonia relative to overall hospital admissions. Results: pneumonia was the leading cause of admissions for respiratory disease, accounting for 57% of all cases and occurring with greater frequency in the rainy season (February to June) and in cities with lower socioeconomic indicator values. The rate of admissions decreased over the study period. Significant clusters (p<0.05) of municipalities with high proportions of hospital admissions for pneumonia relative to overall hospital admissions occurred predominantly in the south of the state, while clusters with low propor-tions were located mainly in and around the metropolitan region of the state capital São Luís. Conclusions: pneumonia was shown to be a key cause of hospitalization in children and its distribution was associated with contextual socioeconomic factors, reflecting the quality of life and health status of children in Maranhão.