Tim Holt

Complexity science: Complexity and clinical care

This is the second in a series of four articles Biological and social systems are inherently complex, so it is hardly surprising that few if any human illnesses can be said to have a single “cause” or “cure.”1 This article applies the principles introduced in the introductory article in this series2 to three specific clinical areas: the control of blood glucose levels in diabetes, the management of diagnostic uncertainty, and health promotion. A complex adaptive system is a collection of individual agents with freedom to act in ways that are not always totally predictable, and whose actions are interconnected so that the action of one part changes the context for other agents.2 In relation to human health and illness there are several levels of such systems. For all these reasons neither illness nor human behaviour is predictable and neither can safely be “modelled” in a simple cause and effect system.3 The human body is not a machine and its malfunctioning cannot be adequately analysed by breaking the …

Effects of exenatide and liraglutide on heart rate, blood pressure and body weight: Systematic review and meta-analysis

Objectives To synthesise current evidence for the effects of exenatide and liraglutide on heart rate, blood pressure and body weight. Design Meta-analysis of available data from randomised controlled trials comparing Glucagon-like peptide-1 (GLP-1) analogues with placebo, active antidiabetic drug therapy or lifestyle intervention. Participants Patients with type 2 diabetes. Outcome measures Weighted mean differences between trial arms for changes in heart rate, blood pressure and body weight, after a minimum of 12-week follow-up. Results 32 trials were included. Overall, GLP-1 agonists increased the heart rate by 1.86 beats/min (bpm) (95% CI 0.85 to 2.87) versus placebo and 1.90 bpm (1.30 to 2.50) versus active control. This effect was more evident for liraglutide and exenatide long-acting release than for exenatide twice daily. GLP-1 agonists decreased systolic blood pressure by −1.79 mm Hg (−2.94 to −0.64) and −2.39 mm Hg (−3.35 to −1.42) compared to placebo and active control, respectively. Reduction in diastolic blood pressure failed to reach statistical significance (−0.54 mm Hg (−1.15 to 0.07) vs placebo and −0.50 mm Hg (−1.24 to 0.24) vs active control). Body weight decreased by −3.31 kg (−4.05 to −2.57) compared to active control, but by only −1.22 kg (−1.51 to −0.93) compared to placebo. Conclusions GLP-1 analogues are associated with a small increase in heart rate and modest reductions in body weight and blood pressure. Mechanisms underlying the rise in heart rate require further investigation.

Clinical workload in UK primary care: a retrospective analysis of 100 million consultations in England, 2007–14

Summary Background Primary care is the main source of health care in many health systems, including the UK National Health Service (NHS), but few objective data exist for the volume and nature of primary care activity. With rising concerns that NHS primary care workload has increased substantially, we aimed to assess the direct clinical workload of general practitioners (GPs) and practice nurses in primary care in the UK. Methods We did a retrospective analysis of GP and nurse consultations of non-temporary patients registered at 398 English general practices between April, 2007, and March, 2014. We used data from electronic health records routinely entered in the Clinical Practice Research Datalink, and linked CPRD data to national datasets. Trends in age-standardised and sex-standardised consultation rates were modelled with joinpoint regression analysis. Findings The dataset comprised 101 818 352 consultations and 20 626 297 person-years of observation. The crude annual consultation rate per person increased by 10·51%, from 4·67 in 2007–08, to 5·16 in 2013–14. Consultation rates were highest in infants (age 0–4 years) and elderly people (≥85 years), and were higher for female patients than for male patients of all ages. The greatest increases in age-standardised and sex-standardised rates were in GPs, with a rise of 12·36% per 10 000 person-years, compared with 0·9% for practice nurses. GP telephone consultation rates doubled, compared with a 5·20% rise in surgery consultations, which accounted for 90% of all consultations. The mean duration of GP surgery consultations increased by 6·7%, from 8·65 min (95% CI 8·64–8·65) to 9·22 min (9·22–9·23), and overall workload increased by 16%. Interpretation Our findings show a substantial increase in practice consultation rates, average consultation duration, and total patient-facing clinical workload in English general practice. These results suggest that English primary care as currently delivered could be reaching saturation point. Notably, our data only explore direct clinical workload and not indirect activities and professional duties, which have probably also increased. This and additional research questions, including the outcomes of workload changes on other sectors of health care, need urgent answers for primary care provision internationally. Funding Department of Health Policy Research Programme.

Telephone triage for management of same-day consultation requests in general practice (the ESTEEM trial): a cluster-randomised controlled trial and cost-consequence analysis.

BACKGROUND Telephone triage is increasingly used to manage workload in primary care; however, supporting evidence for this approach is scarce. We aimed to assess the effectiveness and cost consequences of general practitioner-(GP)-led and nurse-led telephone triage compared with usual care for patients seeking same-day consultations in primary care. METHODS We did a pragmatic, cluster-randomised controlled trial and economic evaluation between March 1, 2011, and March 31, 2013, at 42 practices in four centres in the UK. Practices were randomly assigned (1:1:1), via a computer-generated randomisation sequence minimised for geographical location, practice deprivation, and practice list size, to either GP-led triage, nurse-led computer-supported triage, or usual care. We included patients who telephoned the practice seeking a same-day face-to-face consultation with a GP. Allocations were concealed from practices until after they had agreed to participate and a stochastic element was included within the minimisation algorithm to maintain concealment. Patients, clinicians, and researchers were not masked to allocation, but practice assignment was concealed from the trial statistician. The primary outcome was primary care workload (patient contacts, including those attending accident and emergency departments) in the 28 days after the first same-day request. Analyses were by intention to treat and per protocol. This trial was registered with the ISRCTN register, number ISRCTN20687662. FINDINGS We randomly assigned 42 practices to GP triage (n=13), nurse triage (n=15), or usual care (n=14), and 20,990 patients (n=6695 vs 7012 vs 7283) were randomly assigned, of whom 16,211 (77%) patients provided primary outcome data (n=5171 vs 5468 vs 5572). GP triage was associated with a 33% increase in the mean number of contacts per person over 28 days compared with usual care (2·65 [SD 1·74] vs 1·91 [1·43]; rate ratio [RR] 1·33, 95% CI 1·30-1·36), and nurse triage with a 48% increase (2·81 [SD 1·68]; RR 1·48, 95% CI 1·44-1·52). Eight patients died within 7 days of the index request: five in the GP-triage group, two in the nurse-triage group, and one in the usual-care group; however, these deaths were not associated with the trial group or procedures. Although triage interventions were associated with increased contacts, estimated costs over 28 days were similar between all three groups (roughly £75 per patient). INTERPRETATION Introduction of telephone triage delivered by a GP or nurse was associated with an increase in the number of primary care contacts in the 28 days after a patients request for a same-day GP consultation, with similar costs to those of usual care. Telephone triage might be useful in aiding the delivery of primary care. The whole-system implications should be assessed when introduction of such a system is considered. FUNDING Health Technology Assessment Programme UK National Institute for Health Research.

Risk of stroke and oral anticoagulant use in atrial fibrillation: a cross-sectional survey

BACKGROUND Oral anticoagulants substantially reduce the risk of stroke in atrial fibrillation but are underutilised in current practice. AIM To measure the distribution of stroke risk in patients with atrial fibrillation (using the CHADS(2) and CHA(2)DS(2)-VASc scores) and changes in oral anticoagulant use during 2007-2010. DESIGN AND SETTING Longitudinal series of cross-sectional survey in 583 UK practices linked to the QResearch(®) database providing 99 351 anonymised electronic records from people with atrial fibrillation. METHOD The proportion of patients in each CHADS(2) and CHA(2)DS(2)-VASc risk band in 2010 was calculated; for each of the years 2007-2010, the proportions with risk scores ≥2 that were using anticoagulants or antiplatelet agents were estimated. The proportions identified at high risk were re-estimated using alternative definitions of hypertension based on coded data. Finally, the prevalence of comorbid conditions in treated and untreated high-risk (CHADS(2) ≥2) groups was derived. RESULTS The proportion at high risk of stroke in 2010 was 56.9% according to the CHADS(2) ≥2 threshold, and 84.5% according to CHA(2)DS(2)-VASc ≥2 threshold. The proportions of these groups receiving anticoagulants were 53.0% and 50.7% respectively and increased during 2007-2010. The means of identifying the population of individuals with hypertension significantly influenced the estimated proportion at high risk. Comorbid conditions associated with avoidance of anticoagulants included history of falls, use of nonsteroidal anti-inflammatory drugs, and dementia. CONCLUSION Oral anticoagulant use in atrial fibrillation has increased in UK practice since 2007, but remains suboptimal. Improved coding of hypertension is required to support systematic identification of individuals at high risk of stroke and could be assisted by practice-based software.

Identifying undiagnosed diabetes: cross-sectional survey of 3.6 million patients' electronic records.

BACKGROUND Around 1% of the UK population has diabetes that is either undiagnosed or unrecorded on practice disease registers. AIM To estimate the number of people in UK primary care databases with biochemical evidence of undiagnosed diabetes. To develop simple practice-based search techniques to support early recognition of diabetes. DESIGN OF STUDY Cross-sectional survey of 3 630 296 electronic records. SETTING Four hundred and eighty UK practices contributing to the QRESEARCH database. METHOD Electronic searches to identify people with no diabetes diagnosis in one of two categories (A and B), using the most recently recorded blood glucose measurement: random blood glucose level >or=11.1 mmol/l or fasting blood glucose level >or=7.0 mmol/l (A); either a random or a fasting blood glucose level >or=7.0 mmol/l (B). An additional outcome measure was the proportion of the population with at least one blood glucose measurement in the record. RESULTS The number (percentage) identified in category A was 3758 (0.10% of the total population); the number in category B was 32 785 (0.90%). Projected to a practice of 7000 patients, around eight patients have biochemical evidence of undiagnosed diabetes, and 68 have results suggesting the need for further follow-up. One-third of people aged over 40 years without diabetes have a blood glucose measurement in the past 2 years in their record. CONCLUSION People with possible undiagnosed diabetes are readily identifiable in UK primary care databases through electronic searches using blood glucose data. People with borderline levels, who may benefit from interventions to reduce their risk of progression to diabetes, can also be identified using practice-based software.

Response to 'The appropriation of complexity theory in health care'

John Paley’s article is good teaching material because it illustrates some classic rhetorical moves used in the ancient sport of argumentation. These include the ‘post hoc ergo propter hoc’ fallacy (assuming that if B occurred after A then A must have caused B); the ‘slippery slope’ fallacy (suggesting that the opponent is guilty of A, then taking the audience through a series of small steps in which A becomes B, B becomes C etc, and concluding that the opponent is guilty of Z); the ‘ad hominem’ fallacy (depicting the opponent as ignorant or foolish, and then concluding that everything s/he says is weak and superficial); and the ‘ad populum’ fallacy (appealing to some positive but ill-defined quality to which the audience is assumed to aspire – such as ‘rigour’ or ‘depth of understanding’). It is ironic, for example, that in the very first sentence of a paper which purports to explain complexity theory, Paley draws a direct and linear link between a series of introductory articles which we published back in 2001 and alleged misunderstandings and misapplications of complexity theory by others in the health care field. Paley claims that in our 2001 series, we ‘partially understood’ what he chose to define as the second principle of complexity – that ‘successive states of the system, globally defined, are determined by previous states, locally defined’. We apparently ‘failed to recognize’ what Paley decided was complexity theory’s first principle – that complexity is an explanatory concept. It is presumably coincidental, then, that Paley chose to use the same example (a termite colony) to illustrate this principle as we ourselves used to illustrate it in the first article in our series. Paley’s third principle of complexity is expressed thus: ‘Complexity explanations account for global order by specifying the local behaviour of units which have no awareness of the order thereby being produced, and which have no intention to produce it’. If, as he claims, we ‘failed to recognize’ this, why did we say in our first article ‘Order, innovation, and progress can emerge naturally from the interactions within a complex system; they do not need to be imposed centrally or from outside. For example, termite colonies construct the highest structures on the planet relative to the size of the builders. Yet there is no chief executive termite, no architect termite, and no blueprint. Each individual termite acts locally, seemingly following only a few simple shared rules of behaviour, within a context of other termites also acting locally. The termite mound emerges from a process of self organization’? Paley suggests that in our article on complexity, leadership and management, we misinterpreted the notion of the self-organizing system to mean that bottom-up approaches to organizational strategy and development should replace top-down ones. Had this been true, it would have been a grievous fault. What Plsek and Wilson actually said was ‘Complexity based organizational thinking suggests that goals and resources are established with a view towards the whole system, rather than artificially allocating them to parts of the system’. The article, written at a time when National Service Frameworks and other rigid, nationally imposed performance targets were stifling local initiative and flexibility, was arguing that tight central control can be counterproductive, not that organizations work better with nobody in charge. The analysis of an argument is incomplete without a consideration of the audience for which it was Trisha Greenhalgh MD, Professor of Primary Health Care, University College London, 206 Holborn Union Building, Highgate Hill, London N19 5LW, UK; Paul Plsek MSc, Independent consultant, Paul E. Plsek & Associates, Inc., Atlanta, USA; Tim Wilson FRCGP, Partner, PricewaterhouseCoopers, London, UK; Sarah Fraser DProf, Director, Sarah Fraser & Associates Ltd, Aylesbury, UK; Tim Holt FRCGP, Clinical Lecturer, University of Warwick, Coventry, UK.

Changing Clinical Practice Through Patient Specific Reminders Available at the Time of the Clinical Encounter: Systematic Review and Meta-Analysis

OBJECTIVETo synthesise current evidence for the influence on clinical behaviour of patient-specific electronically generated reminders available at the time of the clinical encounter.DATA SOURCESPubMed, Cochrane library of systematic reviews; Science Citation Index Expanded; Social Sciences Citation Index; ASSIA; EMBASE; CINAHL; DARE; HMIC were searched for relevant articles.STUDY ELIGIBILITY CRITERIA, PARTICIPANTS AND INTERVENTIONSWe included controlled trials of reminder interventions if the intervention was: directed at clinician behaviour; available during the clinical encounter; computer generated (including computer generated paper-based reminders); and generated by patient-specific (rather than condition specific or drug specific) data.STUDY APPRAISAL AND SYNTHESIS METHODSSystematic review and meta-analysis of controlled trials published since 1970. A random effects model was used to derive a pooled odds ratio for adherence to recommended care or achievement of target outcome. Subgroups were examined based on area of care and study design. Odds ratios were derived for each sub-group. We examined the designs, settings and other features of reminders looking for factors associated with a consistent effect.RESULTSAltogether, 42 papers met the inclusion criteria. The studies were of variable quality and some were affected by unit of analysis errors due to a failure to account for clustering. An overall odds ratio of 1.79 [95% confidence interval 1.56, 2.05] in favour of reminders was derived. Heterogeneity was high and factors predicting effect size were difficult to identify.LIMITATIONSMethodological diversity added to statistical heterogeneity as an obstacle to meta-analysis. The quality of included studies was variable and in some reports procedural details were lacking.CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGSThe analysis suggests a moderate effect of electronically generated, individually tailored reminders on clinician behaviour during the clinical encounter. Future research should concentrate on identifying the features of reminder interventions most likely to result in the target behaviour.

The clinical effectiveness and cost-effectiveness of telephone triage for managing same-day consultation requests in general practice: a cluster randomised controlled trial comparing general practitioner-led and nurse-led management systems with usual care (the ESTEEM trial)

BACKGROUND Telephone triage is proposed as a method of managing increasing demand for primary care. Previous studies have involved small samples in limited settings, and focused on nurse roles. Evidence is limited regarding the impact on primary care workload, costs, and patient safety and experience when triage is used to manage patients requesting same-day consultations in general practice. OBJECTIVES In comparison with usual care (UC), to assess the impact of GP-led telephone triage (GPT) and nurse-led computer-supported telephone triage (NT) on primary care workload and cost, patient experience of care, and patient safety and health status for patients requesting same-day consultations in general practice. DESIGN Pragmatic cluster randomised controlled trial, incorporating economic evaluation and qualitative process evaluation. SETTING General practices (n = 42) in four regions of England, UK (Devon, Bristol/Somerset, Warwickshire/Coventry, Norfolk/Suffolk). PARTICIPANTS Patients requesting same-day consultations. INTERVENTIONS Practices were randomised to GPT, NT or UC. Data collection was not blinded; however, analysis was conducted by a statistician blinded to practice allocation. MAIN OUTCOME MEASURES Primary - primary care contacts [general practice, out-of-hours primary care, accident and emergency (A&E) and walk-in centre attendances] in the 28 days following the index consultation request. Secondary - resource use and costs, patient safety (deaths and emergency hospital admissions within 7 days of index request, and A&E attendance within 28 days), health status and experience of care. RESULTS Of 20,990 eligible randomised patients (UC n = 7283; GPT n = 6695; NT n = 7012), primary outcome data were analysed for 16,211 patients (UC n = 5572; GPT n = 5171; NT n = 5468). Compared with UC, GPT and NT increased primary outcome contacts (over 28-day follow-up) by 33% [rate ratio (RR) 1.33, 95% confidence interval (CI) 1.30 to 1.36] and 48% (RR 1.48, 95% CI 1.44 to 1.52), respectively. Compared with GPT, NT was associated with a marginal increase in primary outcome contacts by 4% (RR 1.04, 95% CI 1.01 to 1.08). Triage was associated with a redistribution of primary care contacts. Although GPT, compared with UC, increased the rate of overall GP contacts (face to face and telephone) over the 28 days by 38% (RR 1.38, 95% CI 1.28 to 1.50), GP face-to-face contacts were reduced by 39% (RR 0.61, 95% CI 0.54 to 0.69). NT reduced the rate of overall GP contacts by 16% (RR 0.84, 95% CI 0.78 to 0.91) and GP face-to-face contacts by 20% (RR 0.80, 95% CI 0.71 to 0.90), whereas nurse contacts increased. The increased rate of primary care contacts in triage arms is largely attributable to increased telephone contacts. Estimated overall patient-clinician contact time on the index day increased in triage (GPT = 10.3 minutes; NT = 14.8 minutes; UC = 9.6 minutes), although patterns of clinician use varied between arms. Taking account of both the pattern and duration of primary outcome contacts, overall costs over the 28-day follow-up were similar in all three arms (approximately £75 per patient). Triage appeared safe, and no differences in patient health status were observed. NT was somewhat less acceptable to patients than GPT or UC. The process evaluation identified the complexity associated with introducing triage but found no consistency across practices about what works and what does not work when implementing it. CONCLUSIONS Introducing GPT or NT was associated with a redistribution of primary care workload for patients requesting same-day consultations, and at similar cost to UC. Although triage seemed to be safe, investigation of the circumstances of a larger number of deaths or admissions after triage might be warranted, and monitoring of these events is necessary as triage is implemented. TRIAL REGISTRATION Current Controlled Trials ISRCTN20687662. FUNDING This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 13. See the NIHR Journals Library website for further project information.

The effectiveness and cost-effectiveness of telephone triage of patients requesting same day consultations in general practice: study protocol for a cluster randomised controlled trial comparing nurse-led and GP-led management systems (ESTEEM)

BackgroundRecent years have seen an increase in primary care workload, especially following the introduction of a new General Medical Services contract in 2004. Telephone triage and telephone consultation with patients seeking health care represent initiatives aimed at improving access to care. Some evidence suggests that such approaches may be feasible but conclusions regarding GP workload, cost, and patients’ experience of care, safety, and health status are equivocal. The ESTEEM trial aims to assess the clinical- and cost-effectiveness of nurse-led computer-supported telephone triage and GP-led telephone triage, compared to usual care, for patients requesting same-day consultations in general practice.Methods/designESTEEM is a pragmatic, multi-centre cluster randomised clinical trial with patients randomised at practice level to usual care, computer decision-supported nurse triage, or GP-led triage. Following triage of 350–550 patients per practice we anticipate estimating and comparing total primary care workload (volume and time), the economic cost to the NHS, and patient experience of care, safety, and health status in the 4-week period following the index same-day consultation request across the three trial conditions.We will recruit all patients seeking a non-emergency same-day appointment in primary care. Patients aged 12.0–15.9 years and temporary residents will be excluded from the study.The primary outcome is the number of healthcare contacts taking place in the 4-week period following (and including) the index same-day consultation request. A range of secondary outcomes will be examined including patient flow, primary care NHS resource use, patients’ experience of care, safety, and health status.The estimated sample size required is 3,751 patients (11,253 total) in each of the three trial conditions, to detect a mean difference of 0.36 consultations per patient in the four week follow-up period between either intervention group and usual care 90% power, 5% alpha, and an estimated intracluster correlation coefficient ICC of 0.05. The primary analysis will be based on the intention-to-treat principle and take the form of a random effects regression analysis taking account of the hierarchical nature of the study design. Statistical models will allow for adjustment for practice level minimisation variables and patient-level baseline covariates shown to differ at baseline.Trial registrationCurrent Controlled Trials ISCRTN20687662