Approaches to ascertaining comorbidity information: validation of routine hospital episode data with clinician-based case note review.

BACKGROUND: In clinical practice, research, and increasingly health surveillance, planning and costing, there is a need for high quality information to determine comorbidity information about patients. Electronic, routinely collected healthcare data is capturing increasing amounts of clinical information as part of routine care. The aim of this study was to assess the validity of routine hospital administrative data to determine comorbidity, as compared with clinician-based case note review, in a large cohort of patients with chronic kidney disease. METHODS: A validation study using record linkage. Routine hospital administrative data were compared with clinician-based case note review comorbidity data in a cohort of 3219 patients with chronic kidney disease. To assess agreement, we calculated prevalence, kappa statistic, sensitivity, specificity, positive predictive value and negative predictive value. Subgroup analyses were also performed. RESULTS: Median age at index date was 76.3 years, 44% were male, 67% had stage 3 chronic kidney disease and 31% had at least three comorbidities. For most comorbidities, we found a higher prevalence recorded from case notes compared with administrative data. The best agreement was found for cerebrovascular disease (κ = 0.80) ischaemic heart disease (κ = 0.63) and diabetes (κ = 0.65). Hypertension, peripheral vascular disease and dementia showed only fair agreement (κ = 0.28, 0.39, 0.38 respectively) and smoking status was found to be poorly recorded in administrative data. The patterns of prevalence across subgroups were as expected and for most comorbidities, agreement between case note and administrative data was similar. Agreement was less, however, in older ages and for those with three or more comorbidities for some conditions. CONCLUSIONS: This study demonstrates that hospital administrative comorbidity data compared moderately well with case note review data for cerebrovascular disease, ischaemic heart disease and diabetes, however there was significant under-recording of some other comorbid conditions, and particularly common risk factors.

Definitions of progression in chronic kidney disease--predictors and relationship to renal replacement therapy in a population cohort with a 6 year follow-up.

BACKGROUND: Chronic kidney disease (CKD) is common, important and associated with increased healthcare needs due to CKD progression. Definitions of renal disease progression are multiple, and not always comparable. A measure of 'progression' directly comparable with renal replacement therapy (RRT) initiation would identify 'progressors' in research and for healthcare planning. METHODS: The Grampian Laboratory Outcomes Morbidity and Mortality Study (GLOMMS-I) is a community cohort with CKD from 2003, followed up to June 2009 for (i) RRT initiation and (ii) 'progression': sustained reduction in estimated glomerular filtration rate (eGFR) by 15 mL/min/1.73 m2 (equivalent to CKD stage change), or to <10 mL/min/1.73 m2, whichever occurs first. Predictors were baseline demographics and comorbidity. The use of the Kidney Disease: Improving Global Outcomes-2012 progression definition was also explored. RESULTS: Two thousand two hundred and eighty-nine and 1044 had Stage 3 and 4 CKD, 44% were males. Overall, RRT initiation and progression rates were 0.97 and 3.50 per 100 patient-years (py). Females had significantly lower progression and RRT initiation rates. The progression rate was not dependent on CKD stage [incidence rate ratio (IRR) for Stage 4 (versus Stage 3) 0.9 (95% CI 0.8-1.2)], whereas the RRT initiation rate was [IRR 5.6 (95% CI 3.8-8.2)]. Increased proteinuria was associated with both greater RRT initiation and progression rates. CONCLUSIONS: Progression and RRT initiation rate ratios allow comparison of predictors of these outcomes. Higher rates of both in males suggest that greater RRT initiation rate is biological rather than due to preferential treatment. Similar progression but very different RRT initiation rates in Stage 3 and 4 CKD suggests that CKD stage effect on RRT initiation is a function of endpoint proximity rather than faster renal function deterioration.

Diet behaviour among young people in transition to adulthood (18-25 year olds): a mixed method study.

Background: Young people (18-25 years) during the adolescence/adulthood transition are vulnerable to weight gain and notoriously hard to reach. Despite increased levels of overweight/obesity in this age group, diet behaviour, a major contributor to obesity, is poorly understood. The purpose of this study was to explore diet behaviour among 18-25 year olds with influential factors including attitudes, motivators and barriers. Methods: An explanatory mixed method study design, based on health Behaviour Change Theories was used. Those at University/college and in the community, including those Not in Education, Employment or Training (NEET) were included. An initial quantitative questionnaire survey underpinned by the Theory of Planned Behaviour and Social Cognitive Theory was conducted and the results from this were incorporated into the qualitative phase. Seven focus groups were conducted among similar young people, varying in education and socioeconomic status. Exploratory univariate analysis was followed by multi-staged modelling to analyse the quantitative data. 'Framework Analysis' was used to analyse the focus groups. Results: 1313 questionnaires were analysed. Self-reported overweight/obesity prevalence was 22%, increasing with age, particularly in males. Based on the survey, 40% of young people reported eating an adequate amount of fruits and vegetables and 59% eating regular meals, but 32% reported unhealthy snacking. Based on the statistical modelling, positive attitudes towards diet and high intention (89%), did not translate into healthy diet behaviour. From the focus group discussions, the main motivators for diet behaviour were 'self-appearance' and having 'variety of food'. There were mixed opinions on 'cost' of food and 'taste'. Conclusion: Elements deemed really important to young people have been identified. This mixed method study is the largest in this vulnerable and neglected group covering a wide spectrum of the community. It provides evidence base to inform tailored interventions for a healthy diet within this age group.

Translating chronic kidney disease epidemiology into patient care--the individual/public health risk paradox.

BACKGROUND: Applying the Kidney Disease Outcomes Quality Initiative definitions of chronic kidney disease (CKD), it appears that CKD is common. The increased recognition of CKD has brought with it the clinical challenge of translating into practice the implications for the patient and for service planning. To understand the clinical relevance and translate that into information to support individual patient care and service planning, we explored clinical outcomes in a large British CKD cohort, identified through routine opportunistic testing, with a 6-year follow-up (≈ 13,000 patient-years). METHODS: A cohort had previously been identified with CKD-sustained reduced eGFR over at least 3 months and case note review. Six-year (13,339 patient-years) follow-up for renal replacement therapy (RRT) initiation and death was achieved through data linkage. Age- and sex-specific mortality rates were compared to the general population. RESULTS: Of 3414 individuals (most Stage 3b-5), median age 78.6 years, followed for 13 339 patient-years, 170 (5%) initiated RRT and 2024 (59%) died without initiating RRT. RRT initiation rates decreased with age from 14.33 to 0.65 per 100 patient-years among those aged 15-25 and 75-85 years at baseline but the actual numbers initiating RRT increased from 6 to 34, respectively. RRT initiation rates were lower for female sex, absence of macroalbuminuria and less advanced CKD stage. Mortality rates increased with age from 2 to 34 per 100 patient-years for those aged 15-45 and > 85 years at baseline, an excess of 2 and 17 per 100 patient-years over that of the general population, respectively. However, the increase in relative risk was 19-fold for those aged 15-45 years and just 2-fold in those > 85 years. These data have been converted into simple tools for considering individual patients' risk and informing service planning. CONCLUSIONS: The contrast between relative and absolute risk for both RRT initiation and mortality by age group illustrates the difficulties for planning services. The challenge that now faces clinicians is how to appropriately identify which elderly patients with CKD are at high risk of poor outcome.