1,721,020 research outputs found
Assessing the impact of chronic kidney disease on individuals and populations: use of relative and absolute measures
No full textChronic kidney disease (CKD) is now recognized as a global public health problem, contributing substantially to the burden of non-communicable disease (NCD) [1, 2]. CKD is associated with a variety of NCD outcomes, including renal [end-stage renal disease (ESRD)], cardiovascular and non-cardiovascular. It is important to quantify the risks associated with CKD on such disease outcomes in individuals and the impact of CKD on whole populations, and given the high prevalence of CKD and increased risks of most NCDs at older ages, how the impact of CKD varies by age. The paper by Marks et al. is a population-based study using routinely collected data in the Grampian region of Scotland which aimed to determine the effect of CKD (largely Stage 3b–5) on renal replacement therapy (RRT) and all-cause mortality (ACM). The impact of CKD on RRT and ACM was mainly due to CKD in older age groups, a paradox given that the absolute risk of progression to RRT in the CKD cohort and the relative risks of ACM associated with CKD both fell with age. The findings are firstly an illustration of the contrasting information provided by relative and absolute measures of the effects of risk factors, age and CKD on disease outcomes, and secondly highlight the possible interaction between age and CKD. The authors also developed risk prediction tools to determine the absolute risk of RRT and ACM for patients with CKD. This article considers these concepts in more detail<br/
Is timing of the first antenatal visit associated with adverse birth outcomes? Analysis from a population-based birth cohort
No full textEstimating kidney function in adults using formulae
No full textWith increasing emphasis on the earlier detection and management of chronic kidney disease (CKD), estimation of the glomerular filtration rate (GFR) has assumed greater importance. It is accepted that use of serum creatinine concentration alone as a marker of kidney function is inadequate; in particular, it has a poor sensitivity for detecting CKD. International recommendations favour the reporting of creatinine-based estimates of GFR using formulae which also take into account age, gender and other variables that affect the relationship between serum creatinine and GFR: in particular, the four-variable formula derived from the Modification of Diet in Renal Disease study (4-v MDRD) is increasingly being used. We have reviewed the literature supporting the use of this formula compared with the well-established Cockcroft and Gault formula. Overall, evidence supports the use of the 4-v MDRD formula as an improved estimate of GFR in people with moderate/advanced CKD. Neither formula performs well in people with normal and mildly reduced kidney function. However, there remain significant problems with this approach and areas where further research is required. In particular, the widespread adoption of estimated GFR reporting has refocused attention on the limitations of creatinine measurement and highlighted clinical situations in which the formulae are inadequate
Prediction of childhood overweight and obesity at age 10-11: Findings from the Studying Lifecourse Obesity PrEdictors and the Born in Bradford cohorts
No full textBackground: in England, 41% of children aged 10–11 years live with overweight or obesity. Identifying children at risk of developing overweight or obesity may help target early prevention interventions. We aimed to develop and externally validate prediction models of childhood overweight and obesity at age 10–11 years using routinely collected weight and height measurements at age 4–5 years and maternal and early-life health data.Methods: we used an anonymised linked cohort of maternal pregnancy and birth health records in Hampshire, UK between 2003 and 2008 and child health records. Childhood body mass index (BMI), adjusted for age and sex, at 10–11 years was used to define the outcome of overweight and obesity (BMI ≥ 91st centile) in the models. Logistic regression models and multivariable fractional polynomials were used to select model predictors and to identify transformations of continuous predictors that best predict the outcome. Models were externally validated using data from the Born in Bradford birth cohort. Model performance was assessed using discrimination and calibration.Results: childhood BMI was available for 6566 children at 4–5 (14.6% overweight) and 10–11 years (26.1% overweight) with 10.8% overweight at both timepoints. The area under the curve (AUC) was 0.82 at development and 0.83 on external validation for the model only incorporating two predictors: BMI at 4–5 years and child sex. AUC increased to 0.84 on development and 0.85 on external validation on additionally incorporating maternal predictors in early pregnancy (BMI, smoking, age, educational attainment, ethnicity, parity, employment status). Models were well calibrated.Conclusions: this prediction modelling can be applied at 4–5 years to identify the risk for childhood overweight at 10–11 years, with slightly improved prediction with the inclusion of maternal data. These prediction models demonstrate that routinely collected data can be used to target early preventive interventions to reduce the prevalence of childhood obesity
Associations between chronic kidney disease and age-related macular degeneration
No full textPurpose: age-related macular degeneration (AMD) and renal impairment are both associated with cardiovascular risk factors and with alterations in the complement pathways. There are few data on the association of AMD with chronic kidney disease. Methods: people who were visually impaired (binocular acuity < 6/18) due to AMD (ascertained from review of medical notes; n = 516) were compared to people with normal vision (6/6 or better; n = 2755). Cases with AMD and controls derive from a population-based cross-sectional study of people aged 75 years and over registered with 49 family practices in Britain. Glomerular filtration rate (eGFR) was estimated with the Modification of Diet in Renal Disease formula and proteinuria assessed by dipsticks. Results: after adjusting for a wide range of confounding factors, the presence of proteinuria was positively associated with AMD among men (odds ratio (OR) 2.06, 95% confidence interval (CI) 1.05, 4.04) but not in women (OR 0.62 95%CI 0.36,1.08). Among men, eGFR < 45 ml/min/1.73 m2 was associated with AMD but not after adjusting for proteinuria. This was not observed for women. Both proteinuria and eGFR showed different associations with AMD by sex (p-values for interaction < 0.05). Conclusions: proteinuria appears to be a risk factor for AMD among men but not among women, possibly due to measurement errors in detecting proteinuria in wome
Evaluating screening policies for the early detection of retinopathy in patients with non-insulin dependent diabetes
No full textRetinopathy is a common complication of insulindependent (IDDM) and noninsulindependent (NIDDM) diabetes, but serious visual loss may be prevented or delayed with sufficiently early diagnosis and treatment. Screening for early signs of retinopathy is clearly beneficial for some people, but there is no established consensus about who should be screened, by whom, by what technique and with what frequency, especially for NIDDM. The model described in this paper simulates the development of eye disease in a population of NIDDM patients and the effects of different screening schemes in terms of years of sight saved and the numbers of people prevented from suffering severe visual loss. The initial results indicate that blanket screening of all NIDDM patients may not be effective
Use of antihypertensive medications and mortality of patients with autosomal dominant polycystic kidney disease: a population-based study
No full textBackground: This study aimed to estimate the association between antihypertensive therapy and mortality in patients with autosomal dominant polycystic kidney disease (ADPKD).Study Design: Cohort study.Setting & Participants: Participants with ADPKD from the UK General Practice Research Database older than 15 years between 1991 and 2008.Predictors: Use of 5 major classes of antihypertensive drug.Outcomes: Deaths, new renal replacement therapy events.Measurements: Random-effects Poisson models were adjusted for age, sex, year of entry into the cohort, calendar year, prevalent coronary heart disease, stroke, diabetes, hyperlipidemia, and lipid-lowering therapy.Results: From 1991-2008, there were 2,085 cases of ADPKD, with 1,877 contributing person-time for ages older than 15 years. In 1991, antihypertensive drugs were not prescribed for 68% of participants, which decreased to 38% by 2008. The proportion for which 1 class of antihypertensive drug was prescribed increased from 19% in 1991 to 24% in 2008; 2 classes, from 11% to 22%; 3 classes, from 2% to 11%; and 4 or 5 classes, from 1% to 5%. In 1991, drugs acting on the renin-angiotensin system were prescribed for only 7% of participants; by 2008, this had increased to 46%. There was evidence of a trend toward decreasing mortality as the number of antihypertensive drug classes prescribed in a year increased. For participants with 3 classes of drugs prescribed, the incident rate ratio was 0.11 (95% CI, 0.05-0.21; P < 0.001). Each annual increment in year of entry into the cohort was associated with a 6% (95% CI, 2%-10%; P = 0.008) decrease in mortality.Limitations: Reported associations might be accounted for by unmeasured or incompletely measured confounders. These might include changes in other aspects of medical care for patients with ADPKD.Conclusion: Increasing coverage and intensity of antihypertensive therapy is associated with decreasing mortality in people with ADPKD.<br/
A validation of the National Early Warning Score (NEWS) to predict outcome in patients with COPD exacerbation
No full textBackground: The National Early Warning Score (NEWS), proposed as a standardised track and trigger system, may perform less well in acute COPD exacerbation (AECOPD). This study externally validated NEWS and modifications (CREWS and Salford-NEWS) in AECOPD. Methods: An observational cohort study (2012-2014, two UK acute medical units [AMUs]), compared AECOPD (2,361 admissions, 942 individuals, ICD-10 J40-44 codes) with AMU patients (37,109 admissions, 20,415 individuals). Outcome: in-hospital mortality prediction by admission NEWS, CREWS and Salford-NEWS assessed by discrimination (area under receiver operating characteristic curves [AUCs]) and calibration (plots and Hosmer-Lemeshow [H-L] goodness-of-fit).Results: Median admission NEWS in AECOPD was 4 (IQR 2-6) vs 1 (0-3) for AMU (p=<0.001), despite mortality 4.5% in both. AECOPD AUCs were: NEWS 0.74 (95% confidence intervals 0.66 to 0.82), CREWS 0.72 (0.63 to 0.80) and Salford-NEWS 0.62 (0.53 to 0.70). AMU NEWS AUC was 0.77 (0.75 to 0.78). At threshold NEWS=5 for AECOPD (44% of admissions), positive predictive value (PPV) of death was 8% (5 to 11) and negative predictive value (NPV) 98% (97 to 99) vs AMU patients PPV 17% (16 to 19) and NPV 97% (97 to 97). For NEWS in AECOPD H-L P-value =0.202.Conclusions: This first validation of the NEWS in AECOPD found modest discrimination to predict mortality. Lower specificity of NEWS in AECOPD patients vs other AMU patients reflects acute and chronic respiratory physiological disturbance (including hypoxia), with resultant low PPV at NEWS=5. CREWS and Salford-NEWS, adjusting for chronic hypoxia, increased specificity and PPV but there was no gain in discrimination
Predicting childhood overweight and obesity using maternal and early life risk factors: a systematic review
No full textBackground: Childhood obesity is a serious public health challenge, and identification of high-risk populations with early intervention to prevent its development is a priority. We aimed to systematically review prediction models for childhood overweight/obesity and critically assess the methodology of their development, validation and reporting.Methods: Medline and Embase were searched systematically for studies describing the development and/or validation of a prediction model/score for overweight and obesity between 1 to 13 years of age. Data were extracted using the Cochrane CHARMS checklist for Prognosis Methods.Results: Ten studies were identified that developed (one), developed and validated (seven) or externally validated an existing (two) prediction model. Six out of eight models were developed using automated variable selection methods. Two studies used multiple imputation to handle missing data. From all studies, 30,475 participants were included. Of 25 predictors, only seven were included in more than one model with maternal body mass index, birthweight and gender the most common.Conclusion: Several prediction models exist, but most have not been externally validated or compared with existing models to improve predictive performance. Methodological limitations in model development and validation combined with non-standard reporting restrict the implementation of existing models for the prevention of childhood obesity
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