Benjamin Kearns

Predicting the prevalence of chronic kidney disease in the English population: a cross-sectional study

BackgroundThere is concern that not all cases of chronic kidney disease (CKD) are known to general practitioners, leading to an underestimate of its true prevalence. We carried out this study to develop a model to predict the prevalence of CKD using a large English primary care dataset which includes previously undiagnosed cases of CKD.MethodsCross-sectional analysis of data from the Quality Improvement in CKD trial, a representative sample of 743 935 adults in England aged 18 and over. We created multivariable logistic regression models to identify important predictive factors.ResultsA prevalence of 6.76% was recorded in our sample, compared to a national prevalence of 4.3%. Increasing age, female gender and cardiovascular disease were associated with a significantly increased prevalence of CKD (p < 0.001 for all). Age had a complex association with CKD. Cardiovascular disease was a stronger predictive factor in younger than in older patients. For example, hypertension has an odds ratio of 2.02 amongst patients above average and an odds ratio of 3.91 amongst patients below average age.ConclusionIn England many cases of CKD remain undiagnosed. It is possible to use the results of this study to identify areas with high levels of undiagnosed CKD and groups at particular risk of having CKD.Trial registrationCurrent Controlled Trials ISRCTN: ISRCTN56023731. Note that this study reports the results of a cross-sectional analysis of data from this trial.

Cohort Profile: The Yorkshire Health Study

The Yorkshire Health Study is a longitudinal observational regional health study collecting health information on the residents from the Yorkshire and Humberside region in England. The second wave of data collection is currently under way. The study aims to inform National Health Service (NHS) and local authority health-related decision making in Yorkshire, with wider implications from findings as well. The first wave contains records for 27 806 individuals (2010-12), aged between 16 and 85, from one part of Yorkshire (South Yorkshire), with the second wave expanding data collection to the whole of the Yorkshire and Humberside region. Data were collected on current and long-standing health, health care usage and health-related behaviours, with a particular focus on weight and weight management. The majority of individuals have also given consent for record linkage with routine clinical data, allowing the linking to disease diagnosis, medication use and health care usage. The study encourages researchers to utilize the sample through the embedding of randomized controlled trials, other controlled trials and qualitative studies. To access the anonymized data or use the sample to recruit participants to studies, researchers should contact Clare Relton (c.relton@sheffield.ac.uk).

Enhancements to angioplasty for peripheral arterial occlusive disease: systematic review, cost-effectiveness assessment and expected value of information analysis

BACKGROUND There have been rapid technological developments aimed at improving short- and long-term results of percutaneous transluminal balloon angioplasty (PTA) in peripheral arterial occlusive disease (PAD). OBJECTIVES To assess current clinical effectiveness and cost-effectiveness evidence of additional techniques to standard PTA for PAD, develop a health economic model to assess cost-effectiveness and to identify where further research is needed. DATA SOURCES Relevant electronic databases, including MEDLINE, EMBASE and The Cochrane Library were searched from inception to 2011, between May and October 2011. METHODS Systematic reviews were conducted of clinical effectiveness and cost-effectiveness. The population was participants with symptomatic PAD undergoing endovascular treatment for disease distal to the inguinal ligament. Interventions were modifications of and adjuncts to PTA in the peripheral circulation, compared with conventional PTA. Outcomes included measures of clinical effectiveness and costs. Data were extracted from randomised controlled trials (RCTs), which were quality assessed using standard criteria. Where appropriate, meta-analyses using fixed- and random-effects methods produced relative risks (RRs). A discrete-event simulation model was developed to assess the relative cost-effectiveness of the interventions from a NHS perspective over a lifetime. The patient populations of intermittent claudication (IC) and critical limb ischaemia (CLI) were modelled separately. Univariate and probabilistic sensitivity analyses were undertaken. RESULTS In total, 40 RCTs were included, many of which had small sample sizes. Significantly reduced restenosis rates were shown in meta-analyses of self-expanding stents (SES) {RR 0.67 [95% confidence interval (CI) 0.52 to 0.87]}, endovascular brachytherapy (EVBT) [RR 0.63 (95% CI 0.48 to 0.83)] at 12 months and drug-coated balloons (DCBs) at 6 months [RR 0.40 (95% CI 0.23 to 0.69)], and single studies of stent-graft or drug-eluting stent (DES), compared with PTA; a single study showed improvements with DES versus bare-metal stents (BMSs). Compared with PTA, walking capacity was not significantly affected by cutting balloon, balloon-expandable stents or EVBT; in SES, there was evidence of improvement in walking capacity after up to 12 months. The use of DCBs dominated both the assumed standard practice of PTA with bailout BMS and all other interventions because it lowered lifetime costs and improved quality of life (QoL). These results were seen for both patient populations (IC and CLI). Sensitivity analyses showed that the results were robust to different assumptions about the clinical benefits attributable to the interventions, suggesting that the use of DCBs is cost-saving. LIMITATIONS Differing definitions of restenosis made direct comparison across trials difficult. There were few data available for walking capacity and QoL. CONCLUSIONS The evidence showed a significant benefit to reducing restenosis rates for self-expanding and DESs, stent-graft, EVBT and DCBs. If it is assumed that patency translates into beneficial long-term clinical outcomes, then DCB and bail-out DES are most likely to be the cost-effective enhancements to PTA. A RCT comparing current recommended practice (PTA with bail-out BMS) with DCB and bail-out DES could assess long-term follow-up and cost-effectiveness. Data relating patency status to the need for reintervention and to the probability of symptoms returning should be collected, as should health-related QoL measures [European Quality of Life-5 Dimensions (EQ-5D) and maximum walking distance]. STUDY REGISTRATION This study is registered as PROSPERO CRD42012002014. FUNDING The National Institute for Health Research Health Technology Assessment programme.

Examining the impact of 11 long-standing health conditions on health-related quality of life using the EQ-5D in a general population sample

AbstractObjectives Health-related quality of life (HRQoL) measures have been increasingly used in economic evaluations for policy guidance. We investigate the impact of 11 self-reported long-standing health conditions on HRQoL using the EQ-5D in a UK sample.MethodsWe used data from 13,955 patients in the South Yorkshire Cohort study collected between 2010 and 2012 containing the EQ-5D, a preference-based measure. Ordinary least squares (OLS), Tobit and two-part regression analyses were undertaken to estimate the impact of 11 long-standing health conditions on HRQoL at the individual level.ResultsThe results varied significantly with the regression models employed. In the OLS and Tobit models, pain had the largest negative impact on HRQoL, followed by depression, osteoarthritis and anxiety/nerves, after controlling for all other conditions and sociodemographic characteristics. The magnitude of coefficients was higher in the Tobit model than in the OLS model. In the two-part model, these four long-standing health conditions were statistically significant, but the magnitude of coefficients decreased significantly compared to that in the OLS and Tobit models and was ranked from pain followed by depression, anxiety/nerves and osteoarthritis.ConclusionsPain, depression, osteoarthritis and anxiety/nerves are associated with the greatest losses of HRQoL in the UK population. The estimates presented in this article should be used to inform economic evaluations when assessing health care interventions, though improvements can be made in terms of diagnostic information and obtaining longitudinal data.

Guaiac faecal occult blood test performance at initial and repeat screens in the English Bowel Cancer Screening Programme

Background:In many countries, screening for colorectal cancer (CRC) relies on repeat testing using the guaiac faecal occult blood test (gFOBT). This study aimed to compare gFOBT performance measures between initial and repeat screens.Methods:Data on screening uptake and outcomes from the English Bowel Cancer Screening Programme (BCSP) for the years 2008 and 2011 were used. An existing CRC natural history model was used to estimate gFOBT sensitivity and specificity, and the cost-effectiveness of different screening strategies.Results:The gFOBT sensitivity for CRC was estimated to decrease from 27.35% at the initial screen to 20.22% at the repeat screen. Decreases were also observed for the positive predictive value (8.4–7.2%) and detection rate for CRC (0.19–0.14%). Assuming equal performance measures for both the initial and repeat screens led to an overestimate of the cost effectiveness of gFOBT screening compared with the other screening modalities.Conclusions:Performance measures for gFOBT screening were generally lower in the repeat screen compared with the initial screen. Screening for CRC using gFOBT is likely to be cost-effective; however, the use of different screening modalities may result in additional benefits. Future economic evaluations of gFOBT should not assume equal sensitivities between screening rounds.

The clinical effectiveness of different surveillance strategies to prevent colorectal cancer in people with intermediate-grade colorectal adenomas: a retrospective cohort analysis, and psychological and economic evaluations

BACKGROUND The UK guideline recommends 3-yearly surveillance for patients with intermediate-risk (IR) adenomas. No study has examined whether or not this group has heterogeneity in surveillance needs. OBJECTIVES To examine the effect of surveillance on colorectal cancer (CRC) incidence; assess heterogeneity in risk; and identify the optimum frequency of surveillance, the psychological impact of surveillance, and the cost-effectiveness of alternative follow-up strategies. DESIGN Retrospective multicentre cohort study. SETTING Routine endoscopy and pathology data from 17 UK hospitals (n = 11,944), and a screening data set comprising three pooled cohorts (n = 2352), followed up using cancer registries. SUBJECTS Patients with IR adenoma(s) (three or four small adenomas or one or two large adenomas). PRIMARY OUTCOMES Advanced adenoma (AA) and CRC detected at follow-up visits, and CRC incidence after baseline and first follow-up. METHODS The effects of surveillance on long-term CRC incidence and of interval length on findings at follow-up were examined using proportional hazards and logistic regression, adjusting for patient, procedural and polyp characteristics. Lower-intermediate-risk (LIR) subgroups and higher-intermediate-risk (HIR) subgroups were defined, based on predictors of CRC risk. A model-based cost-utility analysis compared 13 surveillance strategies. Between-group analyses of variance were used to test for differences in bowel cancer worry between screening outcome groups (n = 35,700). A limitation of using routine hospital data is the potential for missed examinations and underestimation of the effect of interval and surveillance. RESULTS In the hospital data set, 168 CRCs occurred during 81,442 person-years (pys) of follow-up [206 per 100,000 pys, 95% confidence interval (CI) 177 to 240 pys]. One surveillance significantly lowered CRC incidence, both overall [hazard ratio (HR) 0.51, 95% CI 0.34 to 0.77] and in the HIR subgroup (n = 9265; HR 0.50, 95% CI 0.34 to 0.76). In the LIR subgroup (n = 2679) the benefit of surveillance was less clear (HR 0.62, 95% CI 0.16 to 2.43). Additional surveillance lowered CRC risk in the HIR subgroup by a further 15% (HR 0.36, 95% CI 0.20 to 0.62). The odds of detecting AA and CRC at first follow-up (FUV1) increased by 18% [odds ratio (OR) 1.18, 95% CI 1.12 to 1.24] and 32% (OR 1.32, 95% CI 1.20 to 1.46) per year increase in interval, respectively, and the odds of advanced neoplasia at second follow-up increased by 22% (OR 1.22, 95% CI 1.09 to 1.36), after adjustment. Detection rates of AA and CRC remained below 10% and 1%, respectively, with intervals to 3 years. In the screening data set, 32 CRCs occurred during 25,745 pys of follow-up (124 per 100,000 pys, 95% CI 88 to 176 pys). One follow-up conferred a significant 73% reduction in CRC incidence (HR 0.27, 95% CI 0.10 to 0.71). Owing to the small number of end points in this data set, no other outcome was significant. Although post-screening bowel cancer worry was higher in people who were offered surveillance, worry was due to polyp detection rather than surveillance. The economic evaluation, using data from the hospital data set, suggested that 3-yearly colonoscopic surveillance without an age cut-off would produce the greatest health gain. CONCLUSIONS A single surveillance benefited all IR patients by lowering their CRC risk. We identified a higher-risk subgroup that benefited from further surveillance, and a lower-risk subgroup that may require only one follow-up. A surveillance interval of 3 years seems suitable for most IR patients. These findings should be validated in other studies to confirm whether or not one surveillance visit provides adequate protection for the lower-risk subgroup of intermediate-risk patients. STUDY REGISTRATION Current Controlled Trials ISRCTN15213649. FUNDING The National Institute for Health Research Health Technology Assessment programme.

Cost-effectiveness of superficial femoral artery endovascular interventions in the UK and Germany: a modelling study

Objectives To assess the lifetime costs and cost-effectiveness of 5 endovascular interventions to treat superficial femoral arterial disease. Design A model-based health economic evaluation. An existing decision analytical model was used, with updated effectiveness data taken from the literature, and updated costs based on purchasing prices. Setting UK and German healthcare perspectives were considered. Participants Patients with intermittent claudication of the femoropopliteal arteries eligible for endovascular treatment. Methods UK and German healthcare perspectives were considered, as were different strategies for re-intervention. Interventions Percutaneous transluminal angioplasty (PTA) with bail-out bare metal stenting (assumed to represent the existing standard of care, and 4 alternatives: primary bare metal stents, drug-eluting stents, drug-eluting balloons (DEBs) and biomimetic stents). Primary outcome measures The incremental cost-effectiveness ratio between 2 treatments, defined as the incremental costs divided by the incremental quality-adjusted life years (QALYs). Results Use of a biomimetic stent, BioMimics 3D, was always estimated to dominate the other interventions, having lower lifetime costs and greater effectiveness, as measured by QALYs. Of the remaining interventions, DEBs were always the most effective, and PTA the least effective. There was uncertainty in the cost-effectiveness results, with key drivers being the costs and effectiveness of the biomimetic stent along with the costs of DEBs. Conclusions All 4 of the alternatives to PTA were more effective, with the biomimetic stent being the most cost-effective. As there was uncertainty in the results, and all of the interventions have different mechanisms of action, all 4 may be considered to be alternatives to PTA.

Factors associated with completion of bowel cancer screening and the potential effects of simplifying the screening test algorithm

Background:The primary colorectal cancer screening test in England is a guaiac faecal occult blood test (gFOBt). The NHS Bowel Cancer Screening Programme (BCSP) interprets tests on six samples on up to three test kits to determine a definitive positive or negative result. However, the test algorithm fails to achieve a definitive result for a significant number of participants because they do not comply with the programme requirements. This study identifies factors associated with failed compliance and modifications to the screening algorithm that will improve the clinical effectiveness of the screening programme.Methods:The BCSP Southern Hub data for screening episodes started in 2006–2012 were analysed for participants aged 60–69 years. The variables included age, sex, level of deprivation, gFOBt results and clinical outcome.Results:The data set included 1 409 335 screening episodes; 95.08% of participants had a definitively normal result on kit 1 (no positive spots). Among participants asked to complete a second or third gFOBt, 5.10% and 4.65%, respectively, failed to return a valid kit. Among participants referred for follow up, 13.80% did not comply. Older age was associated with compliance at repeat testing, but non-compliance at follow up. Increasing levels of deprivation were associated with non-compliance at repeat testing and follow up. Modelling a reduction in the threshold for immediate referral led to a small increase in completion of the screening pathway.Conclusions:Reducing the number of positive spots required on the first gFOBt kit for referral for follow-up and targeted measures to improve compliance with follow-up may improve completion of the screening pathway.

The association between long-term conditions and uptake of population-based screening for colorectal cancer: results from two English cohort studies

Introduction Uptake of screening for colorectal cancer (CRC) can reduce mortality, and population-based screening is offered in England. To date, there is little evidence on the association between having a long-term condition (LTC) and CRC screening uptake. The objective of this study was to examine the association between having an LTC and uptake of CRC screening in England with the guaiac fecal occult blood test, with a particular focus on common mental disorders. Methods The study was a preregistered secondary analysis of two cohorts: first, a linked data set between the regional Yorkshire Health Study (YHS) and the National Health Service National Bowel Cancer Screening Program (BCSP, years 2006–2014); second, the national English Longitudinal Study of Ageing (ELSA, years 2014–2015). Individuals eligible for BCSP screening who participated in either the YHS (7,142) or ELSA Wave 7 (4,099) were included. Study registration: ClinicalTrials.gov, number NCT02503969. Results In both the cohorts, diabetes was associated with lower uptake (YHS odds ratio [OR] for non-uptake 1.35, 95% CI 1.03–1.78; ELSA 1.33, 1.03–1.72) and osteoarthritis was associated with increased uptake (YHS 0.75, 0.57–0.99; ELSA 0.76, 0.62–0.93). After controlling for broader determinants of health, there was no evidence of significantly different uptake for individuals with common mental disorders. Conclusion Two large independent cohorts provided evidence that uptake of CRC screening is lower among individuals with diabetes and higher among individuals with osteoarthritis. Further work should compare barriers and facilitators to screening among individuals with either of these conditions. This study also demonstrates the benefits of data linkage for improving clinical decision-making.