SUMMARYMany countries are currently studying the possibility of mass vaccination against varicella. The objective of this study was to provide a comprehensive picture of the pre-vaccine epidemiology of the varicella zoster virus (VZV) to aid in the design of immunization programs and to adequately measure the impact of vaccination. Population-based data including physician visit claims, sentinel surveillance and hospitalization data from Canada and the United Kingdom were analysed. The key epidemiological characteristics of varicella and zoster (age specific consultation rates, seasonality, force of infection, hospitalization rates and inpatient days) were compared. Results show that the overall epidemiology of varicella and zoster is remarkably similar between the two countries. The major difference being that, contrary to Canada, the epidemiology of varicella seems to be changing in the United Kingdom with an important decrease in the average age at infection that coincides with a significant increase in children attending preschool. Furthermore, differences exist in the seasonality between the United Kingdom and Canada, which seem to be primarily due to the school calendar. These results illustrate that school and preschool contact patterns play an important role in the dynamics of varicella. Finally, our results provide baseline estimates of varicella and zoster incidence and morbidity for VZV vaccine effectiveness and cost-effectiveness studies.

Linked administrative databases offer a powerful resource for studying important public health issues. Methods developed and implemented in several jurisdictions across the globe have achieved high-quality linkages for conducting health and social research without compromising confidentiality. Key data available for linkage include health services utilization, population registries, place of residence, family ties, educational outcomes, and use of social services. Linking events for large populations of individuals across disparate sources and over time permits a range of research possibilities, including the capacity to study lowprevalence exposure-disease associations, multiple outcome domains within the same cohort of individuals, service utilization and chronic disease patterns, and life course and transgenerational transmission of health. Limited information on variables such as individual-level socioeconomic status (SES) and social supports is outweighed by strengths that include comprehensive follow-up, continuous data collection, objective measures, and relatively low expense. Ever advancing methodologies and data holdings guarantee that research using linked administrative databases will make increasingly important contributions to public health research.

OBJECTIVE To evaluate the risk of complications in youth with type 2 diabetes. RESEARCH DESIGN AND METHODS Population-based cohorts of 342 youth (1–18 years of age) with prevalent type 2 diabetes, 1,011 youth with type 1 diabetes, and 1,710 nondiabetic control youth were identified between 1986 and 2007 from a clinical registry and linked to health care records to assess long-term outcomes using ICD-9CM and ICD-10CA codes. RESULTS Youth with type 2 diabetes had an increased risk of any complication (hazard ratio 1.47 [95% CI 1.02–2.12]). Significant adverse clinical factors included age at diagnosis (1.08 [1.02–2.12]), HbA1c (1.06 [1.01–1.12]), and, surprisingly, renin-angiotensin-aldosterone system (RAAS) inhibitor use (1.75 [1.27–2.41]). HNF-1α G319S polymorphism was protective in the type 2 diabetes cohort (0.58 [0.34–0.99]). Kaplan-Meier statistics revealed an earlier diagnosis of renal and neurologic complications in the type 2 diabetes cohort, manifesting within 5 years of diagnosis. No difference in retinopathy was seen. Cardiovascular and cerebrovascular diseases were rare; however, major complications (dialysis, blindness, or amputation) started to manifest 10 years after diagnosis in the type 2 diabetes cohort. Youth with type 2 diabetes had higher rates of all outcomes than nondiabetic control youth and an overall 6.15-fold increased risk of any vascular disease. CONCLUSIONS Youth with type 2 diabetes exhibit complications sooner than youth with type 1 diabetes. Younger age at diagnosis is potentially protective, and glycemic control is an important modifiable risk factor. The unexpected adverse association between RAAS inhibitor use and outcome is likely a confounder by indication; however, further evaluation in young people is warranted.

This paper describes a scoping review of 42 studies of neighborhood effects on developmental health for children ages 0-6, published between 2009 and 2014. It focuses on three themes: (1) theoretical mechanisms that drive early childhood development, i.e. how neighborhoods matter for early childhood development; (2) dependence of such mechanisms on place-based characteristics i.e. where neighborhood effects occur; (3) dependence of such mechanisms on child characteristics, i.e. for whom is development most affected. Given that ecological systems theories postulate diverse mechanisms via which neighborhood characteristics affect early child development, we specifically examine evidence on mediation and/or moderation effects. We conclude by discussing future challenges, and proposing recommendations for analyses that utilize ecological longitudinal population-based databases.

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OBJECTIVETo evaluate renal outcomes and survival in youth with type 2 diabetes (T2DM) versus type 1 diabetes (T1DM) versus nondiabetic control subjects.RESEARCH DESIGN AND METHODSIn total, 342 prevalent youth (aged 1–18 years) with T2DM, 1,011 youth with T1DM, and 1,710 control subjects identified from 1986 to 2007 were anonymously linked to health care records housed at the Manitoba Centre for Health Policy to assess long-term outcomes using ICD codes.RESULTSYouth with T2DM were found to have a fourfold increased risk of renal failure versus youth with T1DM. Risk factors associated with renal failure were renin angiotensin aldosterone system inhibitor use and albuminuria in adolescence. Compared with control subjects (age, sex, and postal code matched), youth with T2DM had a 23-fold increased risk of renal failure and a 39-fold increased risk of dialysis. Kaplan-Meier survival at 10 years was 91.4% in the type 2 diabetic group versus 99.5% in the type 1 diabetic group (P < 0.0001). Renal survival was 100% at 10 years in both groups. It decreased to 92.0% at 15 years and 55.0% at 20 years in the type 2 diabetic group but remained stable in the type 1 diabetic group (P < 0.0001).CONCLUSIONSYouth with T2DM are at high risk of adverse renal outcomes and death. Albuminuria and angiotensin aldosterone system inhibitor use, which may be a marker of severity of disease, are associated with poor outcomes in early adulthood.

Background Animal studies demonstrate general anesthetic (GA) toxicity in the developing brain. Clinical reports raise concern, but the risk of GA exposure to neurodevelopment in children remains uncertain. Methods The authors undertook a retrospective matched cohort study comparing children less than 4 yr of age exposed to GA to those with no GA exposure. The authors used the Early Development Instrument (EDI), a 104-component questionnaire, encompassing five developmental domains, completed in kindergarten as the outcome measure. Mixed-effect logistic regression models generated EDI estimates for single versus multiple GA exposure and compared both single and multiple exposures by the age of 0 to 2 or 2 to 4 yr. Known sociodemographic and physical confounders were incorporated as covariates in the models. Results A total of 18,056 children were studied: 3,850 exposed to a single GA and 620 exposed to two or more GA, who were matched to 13,586 nonexposed children. In children less than 2 yr of age, there was no independent association between single or multiple GA exposure and EDI results. Paradoxically, single exposure between 2 and 4 yr of age was associated with deficits, most significant for communication/general knowledge (estimate, −0.7; 95% CI, −0.93 to −0.47; P &lt; 0.0001) and language/cognition (estimate, −0.34; 95% CI, −0.52 to −0.16; P &lt; 0.0001) domains. Multiple GA exposure at the age of 2 to 4 yr did not confer greater risk than single GA exposure. Conclusions These findings refute the assumption that the earlier the GA exposure in children, the greater the likelihood of long-term neurocognitive risk. The authors cannot confirm an association between multiple GA exposure and increased risk of neurocognitive impairment, increasing the probability of confounding to explain the results.

The large discrepancy in rates of hospitalisation between persons with and without an ID is an indicator of inadequate primary care for this vulnerable population. Decreasing the number of ambulatory care sensitive condition hospitalisations through specialised outpatient programmes for persons with an ID would potentially lead to better health, improved quality of life and cost savings. Future research should include potentially important factors such as disease severity, socio-economic variables and measures of health service organisation in the analysis. International comparisons of ambulatory care sensitive condition hospitalisation rates could point to the benefits and limitations of the health service policy directions adopted by different countries.