Seeking consensus by formal methods: a health warning.
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Clinical Competence↗
Biomedical subjects
Martin Utley
Publications and source records attributed to Martin Utley.
FDG-PET maximum standardised uptake value is associated with variation in survival: analysis of 498 lung cancer patients.
We sought to establish the extent to which tumour uptake of [18F]-fluoro2-deoxy-glucose is associated with survival in patients with primary lung cancer. From our analysis of data concerning 498 lung cancer patients, including surgical and non-surgical cases, we conclude that there is a clear association between higher tumour uptake of glucose and worse survival.
Aged↗
Informing decisions concerning adjuvant chemotherapy following surgical resection for non-small cell lung cancer: a mathematical modelling study.
Faced with the problem of giving individualised advice about adjuvant chemotherapy to patients who have had an apparently curative lung cancer resection, we propose a model to help clarify the choices being made. This would inform the clinician, help the patient and be an explicit basis on which to initiate the discussion.
Antineoplastic Agents↗
MADCAP: a graphical method for assessing risk scoring systems.
OBJECTIVE: We set out to develop a method for assessing the performance of clinical risk models over the spectrum of risks and to assess the performance of the EuroSCORE risk model used in cardiac surgery. METHODS: We developed a graphical method for assessing the performance of clinical risk models over the spectrum of risks. To illustrate the technique, we analysed retrospective data concerning 9268 patients that underwent cardiac surgery and for whom both the additive EuroSCORE prediction of risk of morality and vital status at 30 days were available. RESULTS: The graphical tool developed, called MADCAP (Mean Adjusted Deaths Compared Against Predictions), can be used to highlight systematic features of the performance of a clinical risk model. Its use in the current study indicates that the additive version of the EuroSCORE model seems to underestimate risk amongst low-risk cases (0% and 1%). Otherwise the score systematically favours risk avoiding behaviour as the risk model underestimates mortality for 2--6% prediction but not at 7% and above. CONCLUSION: The robustness of case-mix adjusted audit is dependent on the performance of the risk scoring system over the entire spectrum of risk. If we are to use risk adjustment of mortality rates when comparing outcomes obtained by different units or individual surgeons, it is essential that we continually review the performance of the risk adjustment method. The MADCAP method presented here provides a useful tool to this end.
Cardiac Surgical Procedures↗
A stochastic model to evaluate options for antenatal genetic screening.
Haemoglobinopathies are a group of genetic disorders which are particularly prevalent among certain risk groups such as ethnic groups. Antenatal screening of potential haemoglobinopathy carriers allows early diagnosis for affected fetuses, leading to therapeutic intervention or termination. However, it has drawbacks such as screening costs and possible miscarriage as a result of fetal testing. This paper describes a model that allows the outcomes of a screening programme to be estimated for different risk groups. The model has been implemented as a computer package that can be used to inform decisions made by health care planners.
Female↗
The European Thoracic Surgery Database project: modelling the risk of in-hospital death following lung resection.
OBJECTIVE: To identify pre-operative factors associated with in-hospital mortality following lung resection and to construct a risk model that could be used prospectively to inform decisions and retrospectively to enable fair comparisons of outcomes. METHODS: Data were submitted to the European Thoracic Surgery Database from 27 units in 14 countries. We analysed data concerning all patients that had a lung resection. Logistic regression was used with a random sample of 60% of cases to identify pre-operative factors associated with in-hospital mortality and to build a model of risk. The resulting model was tested on the remaining 40% of patients. A second model based on age and ppoFEV1% was developed for risk of in-hospital death amongst tumour resection patients. RESULTS: Of the 3426 adult patients that had a first lung resection for whom mortality data were available, 66 died within the same hospital admission. Within the data used for model development, dyspnoea (according to the Medical Research Council classification), ASA (American Society of Anaesthesiologists) score, class of procedure and age were found to be significantly associated with in-hospital death in a multivariate analysis. The logistic model developed on these data displayed predictive value when tested on the remaining data. CONCLUSIONS: Two models of the risk of in-hospital death amongst adult patients undergoing lung resection have been developed. The models show predictive value and can be used to discern between high-risk and low-risk patients. Amongst the test data, the model developed for all diagnoses performed well at low risk, underestimated mortality at medium risk and overestimated mortality at high risk. The second model for resection of lung neoplasms was developed after establishing the performance of the first model and so could not be tested robustly. That said, we were encouraged by its performance over the entire range of estimated risk. The first of these two models could be regarded as an evaluation based on clinically available criteria while the second uses data obtained from objective measurement. We are optimistic that further model development and testing will provide a tool suitable for case mix adjustment.
Adult↗
Monitoring the effectiveness of anticoagulation control.
PURPOSE: To assess the quality of anticoagulation control at an out-patient clinic and to investigate patterns of deviation from therapeutic ranges. DESIGN/METHODOLOGY/APPROACH: Records for 36,157 clinic visits (2050 patients) were studied. The quality of anticoagulation control was assessed by comparing the measurement of pro-thrombin time recorded at each clinic visit, expressed as an international normalised ratio (INR), with the target therapeutic range for that patient, also recorded at the time of the clinic visit. Each INR measurement was classified according to the relevant patient's therapeutic range and the signed difference between the INR measurement and the centre of the therapeutic range was calculated. For each patient the percentage of their INR measurements that lay within their therapeutic range was calculated. FINDINGS: Of the measurements, 52.3 per cent were within the relevant therapeutic range. The proportion of individual patients' INR measurements within range varied greatly (median 52 per cent, inter-quartile range 40-65 per cent). The quality of anticoagulation control, as measured by the proportion of patients within their therapeutic range, changed little with patient follow-up time. ORIGINALITY/VALUE: The quality of anticoagulation control reported is comparable with that at other centres. The vast majority of patients spend periods outside the therapeutic range for their condition. There may be considerable room for improvement.
Ambulatory Care↗
Assessment of whether in-hospital mortality for lobectomy is a useful standard for the quality of lung cancer surgery: retrospective study.
OBJECTIVES: To calculate in-hospital mortality after lobectomy for primary lung cancer in the United Kingdom; to explore the validity of using such data to assess the quality of UK thoracic surgeons; and to investigate the relation between in-hospital mortality and the number of procedures performed by surgeons. DESIGN: Retrospective study. SETTING: 36 departments dealing with thoracic surgery in UK hospitals. PARTICIPANTS: 4028 patients who had undergone lobectomy for primary lung cancer by one of 102 surgeons. MAIN OUTCOME MEASURES: In-hospital mortality in relation to individual surgeons, among all patients, and among each of five groups of patients defined by the number of operations performed by the surgeon. RESULTS: 103 patients (2.6%, 95% confidence interval 2.1% to 3.1%) died after surgery during the same hospital admission. No significant difference was found for in-hospital mortality between the five groups. CONCLUSIONS: The number of procedures performed by a thoracic surgeon is not related to in-hospital mortality. Reporting data on in-hospital mortality after lobectomy for primary lung cancer is a poor tool for measuring a surgeon's performance.
Confidence Intervals↗
Analytical methods for calculating the capacity required to operate an effective booked admissions policy for elective inpatient services.
In the UK, hospitals are being encouraged to introduce booked admissions policies for elective inpatient services whereby patients are given a date for hospital admission months in advance rather than being put on a waiting list and then informed of their admission date at short notice. We address the question of what level of capacity is required to operate such a system if cancellations of booked elective patients are to be kept to a low level. Methods are presented for quantifying the day to day variation in bed demand due to emergency admissions, patient initiated cancellations and variable lengths of stay amongst patients.
Admitting Department, Hospital↗
ARMADA--a computer model of the impact of environmental factors on health.
Environmental impact assessments are conducted on many developments as part of the planning process. There is currently wide interest in developing tools for assessing the impact on the health of the local population of proposed developments that will cause environmental changes. A computer model called ARMADA (Age Related Morbidity And Death Analysis) is described that provides a framework for investigating such health impacts. ARMADA generates estimates of age-related patterns of morbidity and mortality within the local population. These estimates incorporate the demographic features of the population in question and base-line information about the incidence of the disease classes being considered.
Age Factors↗
Authors respond to criticisms of booked inpatient admissions and hospital capacity study.
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Health Services Research↗
Booked inpatient admissions and hospital capacity: mathematical modelling study.
OBJECTIVES: To investigate the variability of patients' length of stay in intensive care after cardiac surgery. To investigate potential interactions between such variability, booked admissions, and capacity requirements. DESIGN: Mathematical modelling study using routinely collected data. SETTING: A cardiac surgery department. SOURCE OF DATA: Hospital records of 7014 people entering intensive care after cardiac surgery. MAIN OUTCOME MEASURES: Length of stay in intensive care; capacity requirements of an intensive care unit for a hypothetical booked admission system. RESULTS: Although the vast majority of patients (89.5%) had a length of stay in intensive care of < or = 48 hours, there was considerable overall variability and the distribution of stays has a lengthy tail. A mathematical model of the operation of a hypothetical booking system indicates that such variability has a considerable impact on intensive care capacity requirements, indicating that a high degree of reserve capacity is required to avoid high rates of operation cancellation because of unavailability of suitable postoperative care. CONCLUSION: Despite the considerable enthusiasm for booked admissions systems, queuing theory suggests that caution is required when considering such systems for inpatient admissions. Such systems may well result in frequent operational difficulties if there is a high degree of variability in length of stay and where reserve capacity is limited. Both of these are common in the NHS.
Admitting Department, Hospital↗
Development and evaluation of a single value score to assess global range of motion in juvenile idiopathic arthritis.
OBJECTIVES: To develop a global range of motion score (GROMS) and to investigate the association between this newly developed measure of joint range of motion and physical function in children with active juvenile idiopathic arthritis (JIA). METHODS: Two scales were calculated, 1 measuring 56 selected joints and 1 measuring 10 joints assessed as important to function by experts from the British Paediatric Rheumatology Group. These were measured in 50 patients with JIA whose disability was assessed using the Child Health Assessment Questionnaire (CHAQ). RESULTS: The GROMS measuring all joints and the GROMS measuring 10 joints closely agreed with each other, and both GROMS correlated significantly with the CHAQ (r = -0.52 and -0.62, respectively). CONCLUSION: The 10-joint GROMS is a simple, easy-to-use tool that measures overall change in joint range of motion that affects physical function in JIA.
Adolescent↗