Nigel Hart

Randomised controlled trial of home-based walking programmes at and below current recommended levels of exercise in sedentary adults

Objectives: To determine, using unsupervised walking programmes, the effects of exercise at a level lower than currently recommended to improve cardiovascular risk factors and functional capacity. Design: 12 week randomised controlled trial. Setting: Northern Ireland Civil Service; home-based walking. Participants: 106 healthy, sedentary 40 to 61 year old adults of both sexes. Interventions: Participants were randomly allocated to a walking programme (30 minutes brisk walking three days a week (n = 44) or five days a week (n = 42)) or a control group (n = 20). Participants could choose to walk in bouts of at least 10 minutes. They used pedometers to record numbers of steps taken. Intention to treat analysis of changes within groups was done using paired t tests; extent of change (baseline to 12 week measurements) was compared between groups using analysis of variance and Gabriel’s post hoc test. Main outcome measures: Blood pressure, serum lipids, body mass index, waist:hip ratio, and functional capacity (using a 10 m shuttle walk test). Main results: 89% (93/106) completed the study. Systolic blood pressure and waist and hip circumferences fell significantly both in the three day group (5 mm Hg, 2.6 cm, and 2.4 cm, respectively) and in the five day group (6 mm Hg, 2.5 cm, and 2.2 cm) (p<0.05). Functional capacity increased in both groups (15%; 11%). Diastolic blood pressure fell in the five day group (3.4 mm Hg, p<0.05). No changes occurred in the control group. Conclusions: This study provides evidence of benefit from exercising at a level below that currently recommended in healthy sedentary adults. Further studies are needed of potential longer term health benefits for a wider community from low levels of exercise.

Explaining variation in cancer survival between 11 jurisdictions in the International Cancer Benchmarking Partnership: a primary care vignette survey

Objectives The International Cancer Benchmarking Partnership (ICBP) is a collaboration between 6 countries and 12 jurisdictions with similar primary care-led health services. This study investigates primary care physician (PCP) behaviour and systems that may contribute to the timeliness of investigating for cancer and subsequently, international survival differences. Design A validated survey administered to PCPs via the internet set out in two parts: direct questions on primary care structure and practice relating to cancer diagnosis, and clinical vignettes, assessing management of scenarios relating to the diagnosis of lung, colorectal or ovarian cancer. Participants 2795 PCPs in 11 jurisdictions: New South Wales and Victoria (Australia), British Columbia, Manitoba, Ontario (Canada), England, Northern Ireland, Wales (UK), Denmark, Norway and Sweden. Primary and secondary outcome measures Analysis compared the cumulative proportion of PCPs in each jurisdiction opting to investigate or refer at each phase for each vignette with 1-year survival, and conditional 5-year survival rates for the relevant cancer and jurisdiction. Logistic regression was used to explore whether PCP characteristics or system differences in each jurisdiction affected the readiness to investigate. Results 4 of 5 vignettes showed a statistically significant correlation (p<0.05 or better) between readiness to investigate or refer to secondary care at the first phase of each vignette and cancer survival rates for that jurisdiction. No consistent associations were found between readiness to investigate and selected PCP demographics, practice or health system variables. Conclusions We demonstrate a correlation between the readiness of PCPs to investigate symptoms indicative of cancer and cancer survival rates, one of the first possible explanations for the variation in cancer survival between ICBP countries. No specific health system features consistently explained these findings. Some jurisdictions may consider lowering thresholds for PCPs to investigate for cancer—either directly, or by specialist referral, to improve outcomes.

Systematic review of the effect of diet and exercise lifestyle interventions in the secondary prevention of coronary heart disease.

The effectiveness of lifestyle interventions within secondary prevention of coronary heart disease (CHD) remains unclear. This systematic review aimed to determine their effectiveness and included randomized controlled trials of lifestyle interventions, in primary care or community settings, with a minimum follow-up of three months, published since 1990. 21 trials with 10,799 patients were included; the interventions were multifactorial (10), educational (4), psychological (3), dietary (1), organisational (2), and exercise (1). The overall results for modifiable risk factors suggested improvements in dietary and exercise outcomes but no overall effect on smoking outcomes. In trials that examined mortality and morbidity, significant benefits were reported for total mortality (in 4 of 6 trials; overall risk ratio (RR) 0.75 (95% confidence intervals (CI) 0.65, 0.87)), cardiovascular mortality (3 of 8 trials; overall RR 0.63 (95% CI 0.47, 0.84)), and nonfatal cardiac events (5 of 9 trials; overall RR 0.68 (95% CI 0.55, 0.84)). The heterogeneity between trials and generally poor quality of trials make any concrete conclusions difficult. However, the beneficial effects observed in this review are encouraging and should stimulate further research.

Do practitioners and friends support patients with coronary heart disease in lifestyle change? a qualitative study

BackgroundHealthy lifestyles help to prevent coronary heart disease (CHD) but outcomes from secondary prevention interventions which support lifestyle change have been disappointing. This study is a novel, in-depth exploration of patient factors affecting lifestyle behaviour change within an intervention designed to improve secondary prevention for patients with CHD in primary care using personalised tailored support. We aimed to explore patients’ perceptions of factors affecting lifestyle change within a trial of this intervention (the SPHERE Study), using semi-structured, one-to-one interviews, with patients in general practice.MethodsInterviews (45) were conducted in purposively selected general practices (15) which had participated in the SPHERE Study. Individuals, with CHD, were selected to include those who succeeded in improving physical activity levels and dietary fibre intake and those who did not. We explored motivations, barriers to lifestyle change and information utilised by patients. Data collection and analysis, using a thematic framework and the constant comparative method, were iterative, continuing until data saturation was achieved.ResultsWe identified novel barriers to lifestyle change: such disincentives included strong negative influences of social networks, linked to cultural norms which encouraged consumption of ‘delicious’ but unhealthy food and discouraged engagement in physical activity. Findings illustrated how personalised support within an ongoing trusted patient-professional relationship was valued. Previously known barriers and facilitators relating to support, beliefs and information were confirmed.ConclusionsIntervention development in supporting lifestyle change in secondary prevention needs to more effectively address patients’ difficulties in overcoming negative social influences and maintaining interest in living healthily.

Development of a survey instrument to investigate the primary care factors related to differences in cancer diagnosis between international jurisdictions.

BackgroundSurvival rates following a diagnosis of cancer vary between countries. The International Cancer Benchmarking Partnership (ICBP), a collaboration between six countries with primary care led health services, was set up in 2009 to investigate the causes of these differences. Module 3 of this collaboration hypothesised that an association exists between the readiness of primary care physicians (PCP) to investigate for cancer – the ‘threshold’ risk level at which they investigate or refer to a specialist for consideration of possible cancer – and survival for that cancer (lung, colorectal and ovarian). We describe the development of an international survey instrument to test this hypothesis.MethodsThe work was led by an academic steering group in England. They agreed that an online survey was the most pragmatic way of identifying differences between the jurisdictions. Research questions were identified through clinical experience and expert knowledge of the relevant literature.A survey comprising a set of direct questions and five clinical scenarios was developed to investigate the hypothesis. The survey content was discussed and refined concurrently and repeatedly with international partners. The survey was validated using an iterative process in England. Following validation the survey was adapted to be relevant to the health systems operating in other jurisdictions and translated into Danish, Norwegian and Swedish, and into Canadian and Australian English.ResultsThis work has produced a survey with face, content and cross cultural validity that will be circulated in all six countries. It could also form a benchmark for similar surveys in countries with similar health care systems.ConclusionsThe vignettes could also be used as educational resources. This study is likely to impact on healthcare policy and practice in participating countries.

The contribution of educational class in improving accuracy of cardiovascular risk prediction across European regions: The MORGAM Project Cohort Component

Objective To assess whether educational class, an index of socioeconomic position, improves the accuracy of the SCORE cardiovascular disease (CVD) risk prediction equation. Methods In a pooled analysis of 68 455 40–64-year-old men and women, free from coronary heart disease at baseline, from 47 prospective population-based cohorts from Nordic countries (Finland, Denmark, Sweden), the UK (Northern Ireland, Scotland), Central Europe (France, Germany, Italy) and Eastern Europe (Lithuania, Poland) and Russia, we assessed improvements in discrimination and in risk classification (net reclassification improvement (NRI)) when education was added to models including the SCORE risk equation. Results The lowest educational class was associated with higher CVD mortality in men (pooled age-adjusted HR=1.64, 95% CI 1.42 to 1.90) and women (HR=1.31, 1.02 to 1.68). In men, the HRs ranged from 1.3 (Central Europe) to 2.1 (Eastern Europe and Russia). After adjustment for the SCORE risk, the association remained statistically significant overall, in the UK and Eastern Europe and Russia. Education significantly improved discrimination in all European regions and classification in Nordic countries (clinical NRI=5.3%) and in Eastern Europe and Russia (NRI=24.7%). In women, after SCORE risk adjustment, the association was not statistically significant, but the reduced number of deaths plays a major role, and the addition of education led to improvements in discrimination and classification in the Nordic countries only. Conclusions We recommend the inclusion of education in SCORE CVD risk equation in men, particularly in Nordic and East European countries, to improve social equity in primary prevention. Weaker evidence for women warrants the need for further investigations.

Near infra-red spectroscopy and arterial oxygen extraction at altitude.

The ratio of oxygenated to total haemoglobin (Hb), or rSO2, obtained by near infrared spectroscopy (NIRS), includes both arterial and venous blood of the region examined. The relationship of arterial oxygen extraction, E, and saturation, SaO2, to rSO2 can be expressed, for normally functioning tissue, as E = 1.39 (1 - rSO2/SaO2). Cerebral E, at rest, is constant at lower altitudes but is reduced at 5000 m. This corresponds to constant values of E for SaO2 values above 90% (approximately). E declines linearly for lower SaO2 values, either including measurement at high altitude or at sea level with a reduced inspiratory oxygen concentration. In addition to measurements of brain NIRS resting oxygen extraction of liver, muscle and kidney have also been calculated from NIRS measurements made, on normal inspired air, at sea level and after acute ascent to 2400 m and 5050 m. At 5050 m E was reduced for all four regions but at 2400 m was the same as at sea level for brain, liver and muscle; for the kidney E was elevated at 2400 m. Cerebral oxygen extraction was calculated for rest and the full range of exercise. It was constant at sea level for the lower levels of exercise and, if the calculated extraction value assumptions still hold at lower SaO2 values, reduced for the higher work rates at intermediate altitudes. The present study confirms constancy of oxygen extraction and hence the ratio of oxygen delivery to oxygen consumption (1/E), within physiological limits, and appears to show where those limits lay and, to some extent, show how matters change beyond ordinary physiological limits.

Increased resting bronchial tone in normal subjects acclimatised to altitude

Background: Normal subjects frequently experience troublesome respiratory symptoms when acclimatised to altitude. Bronchial hyperresponsiveness (BHR) and full and partial flow-volume loops were measured before and after ascent to 5000 m altitude to determine if there are changes in resting bronchial tone and BHR that might explain the symptoms. Methods: BHR to histamine was measured using a turbine spirometer to record partial and full flow-volume curves and expressed as log dose slopes. Twenty one subjects were tested at sea level and after acclimatisation at 5000 m altitude. Results: No significant change in log dose slope measurements of forced expiratory volume in 1 second occurred after acclimatisation, and the maximal expiratory flow with 30% of forced vital capacity remaining (MEF30%) rose on the full loop and fell on the partial loop. Their ratio (full divided by partial) rose on average by 0.28 (95% confidence limits 0.14 to 0.42) from the mean (SD) sea level value of 0.87 (0.20). Conclusions: There is no increase in BHR in normal subjects acclimatised to altitude but an increase in resting bronchial tone occurs that could be released by deep inspiration. This may be the result of increased cholinergic tone.

Knowledge or noise? Making sense of General Practitioners’ and Consultant use of 2-week-wait referrals for suspected cancer

Background:Early diagnosis and treatment of cancer is the goal of the 2-week-wait referral pathway (2WW). Variation exists between General Practice use of 2WW and rates of consultant reprioritisation of GP referral from routine to 2WW (Consultant Upgrade). We investigated variation in General Practice and Consultant Upgrade 2WW referral activity.Methods:Data from 185 000 referrals and 29 000 cancers recorded between 2011 and 2013 from the Northern Ireland Cancer Waiting Time database (CaPPS) were analysed to ascertain standardised referral rate ratios, detection rate (DR) (=sensitivity) and conversion rate (CR) (=positive predictive value) for Practice 2WW referrals and Consultant Upgrade 2WW. Metrics were compared using Spearman’s rank correlation co-efficients.Results:There was consistency in Practice and Consultant Upgrade 2WW referral rates over time, though not for annual DR (Spearman’s ρ<0.37) or CR (Spearman’s ρ<0.26). Practice 2WW referral rates correlated negatively with CR and positively with DR while correlations between DR and CR were restricted to single-year comparisons in Practice 2WW. In Consultant Upgrade, 2WW CR and DR were strongly correlated but only when the same cancers were included in both rates.Conclusions:Results suggest ‘random case mix’ explains previously reported associations between CR and DR with more ‘hard to detect’ cancers in some Practices than in others in a given year corresponding to lower DR and CR. Use of Practice and Consultant Upgrade 2WW referral metrics to gauge General Practice performance may be misleading.

Temporary tattoos: a novel OSCE assessment tool

Background:  There are many issues regarding the use of real patients in objective structured clinical examinations (OSCEs). In dermatology OSCE stations, standardised patients (SPs) with clinical photographs are often used. Temporary transfer tattoos can potentially simulate skin lesions when applied to an SP. This study aims to appraise the use of temporary malignant melanoma tattoos within an OSCE framework.