Incidence Hazard Ratios Research Articles

Pediatric thalassemic patients have higher incidence of asthma: A nationwide population-based retrospective cohort study.

IntroductionPatients with hemoglobinopathies have been reported to have higher rates of pulmonary complications. Few studies have investigated the association between thalassemia and asthma in children.MethodsWe used the data of one million individuals randomly selected from the Registry for Beneficiaries of the National Health Insurance Research Database. One thalassemic child was matched with four control children without thalassemia according to sex, birth year, birth season, prematurity, and previous enteroviral infection.ResultsA total of 800 hundred thalassemic children and 3200 controls were included. Children with thalassemia had higher rates of developing asthma (41.81 vs 25.70 per 1000 person-years, P < 0.001) than the non-thalassemia controls with an adjusted hazard ratio of 1.37 (95% confidence interval [CI] = 1.19–1.58). Boys in the thalassemia cohort had a significantly higher adjusted incidence hazard ratio (IRR) of asthma than those in the non-thalassemia cohort (adjusted IRR = 1.45, 95% CI = 1.02–1.73). The risk of atopic and nonatopic asthma was higher in the thalassemia cohort than in the non-thalassemia cohort (IRR = 1.3, 1.61, respectively).ConclusionsChildren with thalassemia were more likely to develop asthma. More attention should be paid to the early diagnosis of asthma and prevention of asthma attacks.

Behavioural change, weight loss and risk of dementia: A longitudinal study

Recent meta-analysis reported higher dementia risks associated with lower body mass index (BMI) and decreasing BMI. We examined to what extent these associations were attenuated by changes in behaviours and local environment. Multilevel discrete time-to-event models examined associations between baseline and change in BMI with dementia detected through prescription medications (source: Department of Human Services), hospitalisations and death certificates among 144,456 participants in the Sax Institute's 45 and Up Study. Models were adjusted for socioeconomic factors and measures of change in adherence to published guidelines for moderate to vigorous physical activity, sleep duration, alcohol, and fruit and vegetable consumption, as well as incidence of cardiometabolic diseases, and indicators of area-level disadvantage and rurality. Data was analysed in 2020. Higher dementia risks (albeit with imprecision) were found among participants who were underweight (Incidence Hazard Ratio (IHR) 1.30, 95%CI=0.86–1.86) and lower risks among those who were overweight (IHR=0.78, 95%CI=0.70–0.86) or obese (IHR=0.72, 95%CI=0.62–0.83) compared with ‘normal’ BMI. A ≥0.8 kg/m2 reduction in BMI associated with IHR=1.81 (95%CI=1.64–2.01) higher dementia risk relative to those with stable BMI. Higher dementia risk with decreasing BMI was fairly consistent relative to baseline BMI category. Adherence to physical activity and sleep duration guidelines were associated with reduced dementia risk, but neither these, nor adjustment for other behaviours and local factors, explained the BMI-dementia association. In conclusion, we replicated the BMI-dementia findings from a recent meta-analysis and provide further support to preventive strategies focussed on increasing physical activity and improving sleep duration. Other potential environmental risk factors outside of socioeconomic and urban/rural circumstances warrant investigation.

Urban green space, tree canopy and 11-year risk of dementia in a cohort of 109,688 Australians

IntroductionUrban greening is a climate change-related policy with considerable health benefits. But do these benefits extend to prevention of dementia and, if so, which types of green space matter? MethodMultilevel discrete time-to-event cohort study of incident Alzheimer’s disease over 11 years among a baseline recruited between January 1, 2006 and December 31, 2009 (the Sax Institute’s 45 and Up Study). Sampled participants for this study (N=109,688) were aged 45 years or older with no record of dementia up to 6 years before baseline, living in the cities of Sydney, Wollongong and Newcastle, Australia. Exposures were percentage total green space, tree canopy and open grass within 1.6-km road network distance buffers at baseline. Outcomes were time-to-first anti-dementia medication prescription (Department of Human Services) or dementia detected during hospitalisation or death up to 31 December 2016 (up to 11 years follow-up). Outcomes were analysed in parallel to triangulate on associations with green space, while testing for bias due to potential under-prescribing of anti-dementia medications. Models were adjusted for baseline person-level factors and area-level socioeconomic disadvantage. ResultsDementia detection varied by case ascertainment method. 1.55% (1,703/109,688) persons were detected using prescribed anti-dementia medications. 3.32% (3,639/109,688) persons were detected during hospitalisation or death via ICD-10 codes. Dementia incidence irrespective of outcome measurement was lower among females, younger participants, those living in couples, with higher qualifications and higher incomes. Dementia risk was lower with more tree canopy when the outcome was measured using hospital and death records (≥30% vs <10% tree canopy incidence hazard ratio (IHR) = 0.86, 95%CI 0.75, 0.99), after adjusting for person-level factors. The opposite association was observed when anti-dementia medications were used to detect dementia (≥30% vs <10% tree canopy IHR = 1.33, 95%CI 1.07, 1.66). Anti-dementia medication-based detection also indicated lower dementia risk with more open grass (≥20% vs <5% IHR = 0.83, 95%CI 0.67, 1.03). Anti-dementia medication prescribing was lower in the highest vs. lowest area-level disadvantage tertile (29.8% vs. 43.7%) among people diagnosed with dementia, indicating potential bias from geographic differences in prescribing practices. Adjusting for area-level disadvantage explained associations between tree canopy, open grass and dementia when detected by anti-dementia medication, but had negligible impact on negative (i.e. potentially protective) association between tree canopy and dementia detected by hospital and death records (≥30% vs <10% tree canopy hazard ratio 0.84, 95%CI 0.72, 0.99). ConclusionsIncreasing urban tree canopy cover may help to reduce the risk of dementia. Replication in contrasting contexts and mediation studies to assess pathways are warranted.

Idiopathic ventricular fibrillation with fragmented QRS complex and J wave in resting electrocardiogram

ObjectiveTo describe the clinical characteristics of idiopathic ventricular fibrillation (IVF) with fragmented QRS complex (f-QRS) and J wave in resting electrocardiogram.MethodsWe reviewed data from 21 case subjects in our hospital who were resuscitated after cardiac arrest due to IVF and assessed the prevalence of f-QRS and J wave in resting electrocardiogram (ECG). All the case subjects were classified among three groups based on the electrocardiographic morphology: group I, both f-QRS and J wave were observed (n = 6), group II, only J wave was observed (n = 9), group III, neither f-QRS nor J wave was observed (n = 6). Population characteristics, history of syncope or sudden cardiac arrest, incidence of ventricular fibrillation (VF), and circumstance of VF were evaluated among the three groups.ResultsThe incidence of index events (syncope, survived cardiac arrest and VF episodes recorded in implantable cardioverter defibrillator (ICD) or pacemakers) was 13.4 ± 5.6 per-year in group I, 10.8 ± 3.9 per-year in group II, and 9.8 ± 4.2 per-year in group III. There were significant differences in incidences among the three groups, the most frequent index events were observed in group I. The hazard ratio for incidence was 3.2 (95%CI, 1.1–7.9; P = 0.01). The history and circumstance of the index events were different among the groups. In group I, all the index events occurred during sleep in early morning. In group II, four subjects suffered VF during strenuous physical activities or agitation state, two during sleep in early morning, three in usual activity. In group III, one subject suffered VF during sleep in early morning, one in agitation state, four in usual activity.ConclusionsThis study suggests that the IVF patients with the combined appearance of f-QRS and J wave in the resting ECG suffer an increased risk of VF, this subgroup of IVF patients has a unique clinical feature.

Effect of Obesity on Incidence of Type 2 Diabetes Declines with Age Among Japanese Women

The present study sought to investigate whether the effect of obesity on the incidence of type 2 diabetes varies with age among Japanese. Employing two independent cohorts, one in Chiba City from 1994 to 2005 and the other in Kashiwa City from 2002 to 2006, the combined effect of body mass index (BMI) and age on the incidence of type 2 diabetes was evaluated by Cox regression analysis. A total of 37,564 and 26,959 subjects were enrolled in the cohorts and the follow-up rate was 94.7% and 93.3%, respectively. In the Chiba cohort, the hazard ratio for incidence of type 2 diabetes was significantly higher in obese subjects (25.0 kg/m(2) < or = BMI) than in normal weight subjects (18.5 kg/m(2) < or = BMI < 25.0 kg/m(2)) across all age groups, with the highest hazard ratio observed in the youngest group aged 40-59 years. In the Kashiwa cohort, the hazard ratio was also significantly higher in obese subjects than in normal weight subjects in men aged 40-59 and 70-79 years and in women aged 40-59 years. Analysis for the interaction between age groups and obese subjects versus normal weight subjects revealed significant weakening of the effect of obesity in women in both cohorts in subjects aged 60-69 and 70-79 years compared to younger subjects aged 40-59 years. In men, however, a significant weakening of the effect was observed only in subjects aged 60-69 years in the Chiba cohort. The interaction between four BMI categories including an extremely obese group (30.0 kg/m(2) < or = BMI) and age category was significant in women (P < 0.001) but not in men (P = 0.113) in the Chiba cohort. Based on data from the two independent cohorts, the effect of obesity on the incidence of type 2 diabetes was found to decline with age in Japanese women but not in men.