Daniel Lasserson

Global Prevalence of Chronic Kidney Disease – A Systematic Review and Meta-Analysis

Chronic kidney disease (CKD) is a global health burden with a high economic cost to health systems and is an independent risk factor for cardiovascular disease (CVD). All stages of CKD are associated with increased risks of cardiovascular morbidity, premature mortality, and/or decreased quality of life. CKD is usually asymptomatic until later stages and accurate prevalence data are lacking. Thus we sought to determine the prevalence of CKD globally, by stage, geographical location, gender and age. A systematic review and meta-analysis of observational studies estimating CKD prevalence in general populations was conducted through literature searches in 8 databases. We assessed pooled data using a random effects model. Of 5,842 potential articles, 100 studies of diverse quality were included, comprising 6,908,440 patients. Global mean(95%CI) CKD prevalence of 5 stages 13·4%(11·7–15·1%), and stages 3–5 was 10·6%(9·2–12·2%). Weighting by study quality did not affect prevalence estimates. CKD prevalence by stage was Stage-1 (eGFR>90+ACR>30): 3·5% (2·8–4·2%); Stage-2 (eGFR 60–89+ACR>30): 3·9% (2·7–5·3%); Stage-3 (eGFR 30–59): 7·6% (6·4–8·9%); Stage-4 = (eGFR 29–15): 0·4% (0·3–0·5%); and Stage-5 (eGFR<15): 0·1% (0·1–0·1%). CKD has a high global prevalence with a consistent estimated global CKD prevalence of between 11 to 13% with the majority stage 3. Future research should evaluate intervention strategies deliverable at scale to delay the progression of CKD and improve CVD outcomes.

Diagnostic strategies used in primary care

The strategies used by general practitioners in making a diagnosis are being formally recognised; this article is the first in a series that will illustrate their application, and is accompanied by a case study (doi:10.1136/bmj.b1187)

Which features of primary care affect unscheduled secondary care use? A systematic review

Objectives To conduct a systematic review to identify studies that describe factors and interventions at primary care practice level that impact on levels of utilisation of unscheduled secondary care. Setting Observational studies at primary care practice level. Participants Studies included people of any age of either sex living in Organisation for Economic Co-operation and Development (OECD) countries with any health condition. Primary and secondary outcome measures The primary outcome measure was unscheduled secondary care as measured by emergency department attendance and emergency hospital admissions. Results 48 papers were identified describing potential influencing features on emergency department visits (n=24 studies) and emergency admissions (n=22 studies). Patient factors associated with both outcomes were increased age, reduced socioeconomic status, lower educational attainment, chronic disease and multimorbidity. Features of primary care affecting unscheduled secondary care were more complex. Being able to see the same healthcare professional reduced unscheduled secondary care. Generally, better access was associated with reduced unscheduled care in the USA. Proximity to healthcare provision influenced patterns of use. Evidence relating to quality of care was limited and mixed. Conclusions The majority of research was from different healthcare systems and limited in the extent to which it can inform policy. However, there is evidence that continuity of care is associated with reduced emergency department attendance and emergency hospital admissions.

Influence of general practice opening hours on delay in seeking medical attention after transient ischaemic attack (TIA) and minor stroke: prospective population based study.

Objective To assess the influence of general practice opening hours on healthcare seeking behaviour after transient ischaemic attack (TIA) and minor stroke and feasibility of clinical assessment within 24 hours of symptom onset. Design Population based prospective incidence study (Oxford vascular study). Setting Nine general practices in Oxfordshire. Participants 91 000 patients followed from 1 April 2002 to 31 March 2006. Main outcome measures Events that occurred overnight and at weekends (out of hours) and events that occurred during surgery hours. Results Among 359 patients with TIA and 434 with minor stroke, the median (interquartile range) time to call a general practitioner after an event during surgery hours was 4.0 (1.0-45.5) hours, and 68% of patients with events during surgery hours called within 24 hours of onset of symptoms. Median (interquartile range) time to call a general practitioner after events out of hours was 24.8 (9.0-54.5) hours for patients who waited to contact their registered practice compared with 1.0 (0.3-2.6) hour in those who used an emergency general practitioner service (P<0.001). In patients with events out of hours who waited to see their own general practitioner, seeking attention within 24 hours was considerably less likely for events at weekends than weekdays (odds ratio 0.10, 95% confidence interval 0.05 to 0.21): 70% with events Monday to Friday, 33% on Sundays, and none on Saturdays. Thirteen patients who had events out of hours and did not seek emergency care had a recurrent stroke before they sought medical attention. A primary care centre open 8 am-8 pm seven days a week would have offered cover to 73 patients who waited until surgery hours to call their general practitioner, reducing median delay from 50.1 hours to 4.0 hours in that group and increasing those calling within 24 hours from 34% to 68%. Conclusions General practitioners’ opening hours influence patients’ healthcare seeking behaviour after TIA and minor stroke. Current opening hours can increase delay in assessment. Improved access to primary care and public education about the need for emergency care are required if the relevant targets in the national stroke strategy are to be met.

Chronic kidney disease: a large-scale population-based study of the effects of introducing the CKD-EPI formula for eGFR reporting

Objective To evaluate the effects of introducing the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) formula for estimated glomerular filtration rate (eGFR) reporting in the adult population in routine clinical practice with clinician-directed testing. Design Retrospective study of all creatinine measurements and calculation of eGFRs using Modification of Diet in Renal Disease (MDRD) and CKD-EPI formulae. Setting General population, Oxfordshire, UK. Participants An unselected population of around 660 000. Interventions Reporting of eGFRs using MDRD or CKD-EPI formulae. Primary and secondary outcome measures Evaluation of the effects of the CKD-EPI formula on the prevalence of different stages of chronic kidney disease (CKD). Results The CKD-EPI formula reduced the prevalence of CKD (stages 2–5) by 16.4% in patients tested in primary care. At the important stage 2–stage 3 cut-off, there was a relative reduction of 7.5% in the prevalence of CKD stages 3–5 from 15.7% to 14.5%. The CKD-EPI formula reduced the prevalence of CKD stages 3–5 in those aged <70 but increased it at ages >70. Above 70 years, the prevalence of stages 3–5 was similar with both equations for women (around 41.2%) but rose in men from 33.3% to 35.5%. CKD stages 4–5 rose by 15% due exclusively to increases in the over 70s, which could increase specialist referral rates. The CKD classification of 18.3% of all individuals who had a creatinine measurement was altered by a change from the MDRD to the CKD-EPI formula. In the UK population, the classification of up to 3 million patients could be altered, the prevalence of CKD could be reduced by up to 1.9 million and the prevalence of CKD stages 3–5 could fall by around 200 000. Conclusions Introduction of the CKD-EPI formula for eGFR reporting will reduce the prevalence of CKD in a primary care setting with current testing practice but will raise the prevalence in the over 70s age group. This has implications for clinical practice, healthcare policy and current prevalence-based funding arrangements.

Assessment of central haemomodynamics from a brachial cuff in a community setting

BackgroundLarge artery stiffening and wave reflections are independent predictors of adverse events. To date, their assessment has been limited to specialised techniques and settings. A new, more practical method allowing assessment of central blood pressure from waveforms recorded using a conventional automated oscillometric monitor has recently been validated in laboratory settings. However, the feasibility of this method in a community based setting has not been assessed.MethodsOne-off peripheral and central haemodynamic (systolic and diastolic blood pressure (BP) and pulse pressure) and wave reflection parameters (augmentation pressure (AP) and index, AIx) were obtained from 1,903 volunteers in an Austrian community setting using a transfer-function like method (ARCSolver algorithm) and from waveforms recorded with a regular oscillometric cuff. We assessed these parameters for known differences and associations according to gender and age deciles from <30 years to >80 years in the whole population and a subset with a systolic BP < 140 mmHg.ResultsWe obtained 1,793 measures of peripheral and central BP, PP and augmentation parameters. Age and gender associations with central haemodynamic and augmentation parameters reflected those previously established from reference standard non-invasive techniques under specialised settings. Findings were the same for patients with a systolic BP below 140 mmHg (i.e. normotensive). Lower values for AIx in the current study are possibly due to differences in sampling rates, detection frequency and/or averaging procedures and to lower numbers of volunteers in younger age groups.ConclusionA novel transfer-function like algorithm, using brachial cuff-based waveform recordings, provides robust and feasible estimates of central systolic pressure and augmentation in community-based settings.

Relative impact of clinical evidence and over-the-counter prescribing on topical antibiotic use for acute infective conjunctivitis

BACKGROUND Acute infective conjunctivitis is a common presentation in general practice. In 2005, three placebo-controlled clinical trials showed that use of topical antibiotics had a small effect on time to clinical resolution. In the same year, chloramphenicol eye drops were made available for sale over the counter. AIM To compare the relative impact of clinical trial evidence and a change to over-the-counter availability on community use of topical chloramphenicol. DESIGN OF STUDY Observational study using mainly routinely collected data for England. SETTING National prescribing data for England and local data from general practices in Oxfordshire, England. METHOD Data were collated from three sources: GP prescriptions from the Prescription Pricing Authority, wholesale supply to pharmacists from IMS Health, and an audit of delayed prescribing and non-prescribing from electronic consultation records for acute conjunctivitis, in four general practices. RESULTS The number of general practice prescriptions for topical chloramphenicol fell from 2.3 million in 2004 to 1.9 million in 2007, a reduction of 15.5%. In contrast, over-the-counter sales by pharmacists have increased steadily. The net effect of these changes has been a 47.8% increase in total chloramphenicol use during 2005-2007, with 1.1 million additional packs being used in 2007 compared to 2004. CONCLUSION Making an antibiotic available over the counter increases its use substantially. This is in conflict with the important public health message that antibiotic use needs to be reduced to combat resistance. These findings support the views of the Chief Medical Officer that no more antibiotics should currently be made available over the counter.

The evidence underpinning sports performance products: a systematic assessment

Background To assess the extent and nature of claims regarding improved sports performance made by advertisers for a broad range of sports-related products, and the quality of the evidence on which these claims are based. Methods The authors analysed magazine adverts and associated websites of a broad range of sports products. The authors searched for references supporting the performance and/or recovery claims of these products. The authors critically appraised the methods in the retrieved references by assessing the level of evidence and the risk of bias. The authors also collected information on the included participants, adverse events, study limitations, the primary outcome of interest and whether the intervention had been retested. Results The authors viewed 1035 web pages and identified 431 performance-enhancing claims for 104 different products. The authors found 146 references that underpinned these claims. More than half (52.8%) of the websites that made performance claims did not provide any references, and the authors were unable to perform critical appraisal for approximately half (72/146) of the identified references. None of the references referred to systematic reviews (level 1 evidence). Of the critically appraised studies, 84% were judged to be at high risk of bias. Randomisation was used in just over half of the studies (58.1%), allocation concealment was only clear in five (6.8%) studies; and blinding of the investigators, outcome assessors or participants was only clearly reported as used in 20 (27.0%) studies. Only three of the 74 (2.7%) studies were judged to be of high quality and at low risk of bias. Conclusions The current evidence is not of sufficient quality to inform the public about the benefits and harms of sports products. There is a need to improve the quality and reporting of research, a move towards using systematic review evidence to inform decisions.

Life interrupted and life regained? Coping with stroke at a young age

Stroke is a leading cause of disability across the developed world, affecting an increasing number of younger people. In this article, we seek to understand the experience of stroke as a disabling life situation among young people and the strategies that they use to recover and cope. Directed content analysis was conducted from interviews with 17 community-dwelling stroke survivors aged 55 years and younger across the United Kingdom. The sample was drawn from a larger maximum variation sample of stroke survivors. Using the sociological concepts of biographical disruption and biographical repair as a guide, excerpts from the interviews pertaining to aspects of the patients’ life that were interrupted, in addition to how they coped with the changes, were selected and analysed. All individuals described an “altered sense of self,” a theme that included loss of identity, family disruption, and/or loss of valued activities. Individuals sought to adapt their sense of self by seeking external support, by restoring normality, and/or through positive reflection. Despite the adapted self that emerged, most individuals continued to experience impairments. While young stroke survivors adapt to their illness over time, they continue to experience impairments and disruptions in their personal and work lives. A holistic model of rehabilitation that helps individuals regain the capacity for everyday activities related to work, family life, and leisure can begin to address the emotional ramifications of diseases such as stroke, restore wellness, and work towards minimizing the burden felt by family caregivers and children.

Clinical prediction rules in practice: review of clinical guidelines and survey of GPs

BACKGROUND The publication of clinical prediction rules (CPRs) studies has risen significantly. It is unclear if this reflects increasing usage of these tools in clinical practice or how this may vary across clinical areas. AIM To review clinical guidelines in selected areas and survey GPs in order to explore CPR usefulness in the opinion of experts and use at the point of care. DESIGN AND SETTING A review of clinical guidelines and survey of UK GPs. METHOD Clinical guidelines in eight clinical domains with published CPRs were reviewed for recommendations to use CPRs including primary prevention of cardiovascular disease, transient ischaemic attack (TIA) and stroke, diabetes mellitus, fracture risk assessment in osteoporosis, lower limb fractures, breast cancer, depression, and acute infections in childhood. An online survey of 401 UK GPs was also conducted. RESULTS Guideline review: Of 7637 records screened by title and/or abstract, 243 clinical guidelines met inclusion criteria. CPRs were most commonly recommended in guidelines regarding primary prevention of cardiovascular disease (67%) and depression (67%). There was little consensus across various clinical guidelines as to which CPR to use preferentially. SURVEY Of 401 responders to the GP survey, most were aware of and applied named CPRs in the clinical areas of cardiovascular disease and depression. The commonest reasons for using CPRs were to guide management and conform to local policy requirements. CONCLUSION GPs use CPRs to guide management but also to comply with local policy requirements. Future research could focus on which clinical areas clinicians would most benefit from CPRs and promoting the use of robust, externally validated CPRs.