Biomedical subjects

Sally Hollis

Publications and source records attributed to Sally Hollis.

9 recordsLinked to original sources

PubMed2006

Outcome prediction in trauma.

BACKGROUND: In the Trauma Audit and Research Network (TARN), currently the largest trauma network in Europe, outcome prediction is performed using the TRISS methodology since 1989. Its database contains 200,000 hospital admissions from 110 hospitals over the country, but a large amount of data is lost for the modelling because of missing data. To improve some of the shortcomings of TRISS a new model was developed. METHODS: The data for modelling consisted of 100,399 hospital trauma admissions over the period 1996 to 2001. Using the Glasgow Coma Score (GCS) instead of RTS has dramatically reduced the number of missing cases. Gender and its interaction with age have also been included in the model. The model was tested on different subsets of cases traditionally excluded, such as children, those with penetrating injuries, and ventilated and transferred patients. The new model included all those subsets using age, a transformation of ISS, GCS, gender and gender by age interaction as predictors. RESULTS: The model has shown a good discriminant ability tested by the area under the receiver operating characteristic (AROC) curve. The values of the AROC for the new model were 0.947 (95% CI: 0.943-0.951) on the prediction set and 0.952 (95% CI: 0.946-0.957) on the validation set compared respectively with 0.937 (95% CI: 0.932-0.943) and 0.941 (95% CI: 0.936-0.952) for TRISS. CONCLUSION: The new model has enabled us to include most of the cases that were excluded under the TRISS's inclusion criteria, less missing data are incurred and the predictive performance was significantly better than that of the TRISS model as shown by the AROC curves.

Adolescent↗

PubMed2006

Systematic review of rosacea treatments.

BACKGROUND: Rosacea is a common chronic skin and ocular condition. It is unclear which treatments are most effective. We have conducted a Cochrane review of rosacea therapies. This article is a distillation of that work. OBJECTIVE: We sought to assess the evidence for the efficacy and safety of rosacea therapies. METHODS: Multiple databases were systematically searched. Randomized controlled trials in people with moderate to severe rosacea were included. Study selection, assessment of methodologic quality, data extraction, and analysis were carried out by two independent researchers. RESULTS: In all, 29 studies met inclusion criteria. Topical metronidazole is more effective than placebo (odds ratio 5.96, 95% confidence interval 2.95-12.06). Azelaic acid is more effective than placebo (odds ratio 2.45, 95% confidence interval 1.82-3.28). Firm conclusions could not be drawn about other therapies. LIMITATIONS: The quality of the studies was generally poor. CONCLUSIONS: There is evidence that topical metronidazole and azelaic acid are effective. There is some evidence that oral metronidazole and tetracycline are effective. More well-designed, randomized controlled trials are required to provide better evidence of the efficacy and safety of other rosacea therapies.

Administration, Cutaneous↗

PubMed2006

A new approach to outcome prediction in trauma: A comparison with the TRISS model.

BACKGROUND: The Trauma Audit & Research Network (TARN) has been using the TRISS methodology since 1989. Its database contains 200,000 hospital admissions from 110 hospitals over the country. To improve outcome prediction, a revision of the current model became necessary. Our model tried to overcome some of the concerns of the trauma community, namely missing data, functional form of the predictors, inclusion criteria and patient's death within 30 days. METHODS: The data for modeling consisted of 100,399 anonymized hospital trauma admissions during the period 1996 to 2001. Cross validation was performed on this data set, and a multiple logistic regression model was derived using the prediction set and then its prediction ability was tested on the validation set. Fractional polynomials modeling showed that the linear functional form of the Injury Severity Score (ISS) in the model was not satisfactory. Using the Glasgow Coma Score (GCS) instead of the revised trauma score (RTS) has dramatically reduced the number of missing cases. Sex and its interaction with age have also been included in the model. The model was tested on different subsets of cases, traditionally excluded, such as children, those with penetrating injuries, and ventilated and transferred patients. The new model included all those subsets using age, a transformation of ISS, GCS, sex, and sex by age interaction as predictors. RESULTS: The model has shown a good discriminant ability tested by the Area under the Receiver Operating Characteristic (AROC) curve. The values of the AROC for the new model were 0.947 (95% confidence interval [CI]: 0.943-0.951) on the prediction set and 0.952 (95% CI: 0.946-0.957) on the validation set compared, respectively, with 0.937 (95% CI: 0.932-0.943) and 0.941 (95% CI: 0.936-0.952) for TRISS. CONCLUSION: The new model has enabled us to include most of the cases that were excluded under the TRISSs inclusion criteria, less missing data are incurred and the predictive performance was significantly better than that of the TRISS model as shown by the AROC curves.

Adolescent↗

PubMed2006

The effect of pre-existing medical conditions and age on mortality after injury.

BACKGROUND: Pre-existing medical conditions (PMCs) have been shown to increase mortality after trauma even after adjustment for the effect of chronological aging. It has been suggested that there is an interaction between injury severity and physiologic reserve, such that diminished physiologic reserve will have an adverse effect on survival at lower injury severity, but that at higher levels of injury severity, physiologic reserve will have much less of an impact. METHODS: Records of 65,743 patients, admitted after trauma, were extracted from the database of the United Kingdom Trauma Network to explore the impacts of age, gender and PMCs on mortality, and modification of these effects by severity of injury. RESULTS: PMCs were categorized as absent (23%), present (23%), or unrecorded (54%). There was an increase in mortality with increasing age at all levels of injury severity. Presence of a PMC was associated with a marked increase in mortality of patients with minor injuries (odds ratio [OR] = 5.9, 95% confidence interval [CI] 4.4, 8.0) or moderate injuries (OR = 2.0, 95% CI 1.4, 2.9), but not in those with more severe injuries (OR = 1.1, 95% CI 0.9, 1.4). The impact of age and male gender were also somewhat more pronounced for patients with less severe injuries. CONCLUSION: These findings support the hypothesis of an interaction between physiologic reserve and injury severity, where PMCs are associated with increased mortality when combined with low to moderate severity injuries, but not when combined with more severe injuries.

Adolescent↗

PubMed2005

Uncertainty method improved on best-worst case analysis in a binary meta-analysis.

BACKGROUND: Most systematic reviewers aim to perform an intention-to-treat meta-analysis, including all randomized participants from each trial. This is not straightforward in practice: reviewers must decide how to handle missing outcome data in the contributing trials. OBJECTIVE: To investigate methods of allowing for uncertainty due to missing data in a meta-analysis. STUDY DESIGN AND SETTING: The Cochrane Library was surveyed to assess current use of imputation methods. We developed a methodology for incorporating uncertainty, with weights assigned to trials based on uncertainty interval widths. The uncertainty interval for a trial incorporates both sampling error and the potential impact of missing data. We evaluated the performance of this method using simulated data. RESULTS: The survey showed that complete-case analysis is commonly considered alongside best-worst case analysis. Best-worst case analysis gives an interval for the treatment effect that includes all of the uncertainty due to missing data. Unless there are few missing data, this interval is very wide. Simulations show that the uncertainty method consistently has better power and narrower interval widths than best-worst case analysis. CONCLUSION: The uncertainty method performs consistently better than best-worst case imputation and should be considered along with complete-case analysis whenever missing data are a concern.

Antimalarials↗

PubMed2005

Pro-active call center treatment support (PACCTS) to improve glucose control in type 2 diabetes: a randomized controlled trial.

OBJECTIVE: To determine whether Pro-Active Call Center Treatment Support (PACCTS), using trained nonmedical telephonists supported by specially designed software and a diabetes nurse, can effectively improve glycemic control in type 2 diabetes. RESEARCH DESIGN AND METHODS: A randomized controlled implementation trial of 1-year duration was conducted in Salford, U.K. The trial comprised 591 randomly selected individuals with type 2 diabetes. By random allocation, 197 individuals were assigned to the usual care (control) group and 394 to the PACCTS (intervention) group. Lifestyle advice and drug treatment in both groups followed local guidelines. PACCTS patients were telephoned according to a protocol with the frequency of calls proportional to the last HbA(1c) level. The primary outcome was absolute reduction in HbA(1c), and the secondary outcome was the proportion of patients reducing HbA(1c) by at least 1%. RESULTS: A total of 332 patients (84%) in the PACCTS group and 176 patients (89%) in the control group completed the study. Final HbA(1c) values were available in 374 patients (95%) in the PACCTS group and 180 patients (92%) in the usual care group. Compared with usual care, HbA(1c) improved by 0.31% (95% CI 0.11-0.52, P = 0.003) overall in the PACCTS patients. For patients with baseline HbA(1c) >7%, the improvement increased to 0.49% (0.21-0.77, P < 0.001), whereas in patients with baseline HbA(1c) <7% there was no change. The difference in the proportions of patients achieving a >/=1% reduction in HbA(1c) significantly favored the PACCTS intervention: 10% (4-16, P < 0.001) overall and 15% (7-24, P < 0.001) for patients with baseline HbA(1c) >7%. CONCLUSIONS: In an urban Caucasian trial population with blood glucose HbA(1c) >7%, PACCTS facilitated significant improvement in glycemic control. Further research should extend the validity of findings to rural communities and other ethnic groups, as well as to smoking and lipid and blood pressure control.

Adult↗

PubMed2004

Abnormalities on magnetic resonance imaging seen acutely following mild traumatic brain injury: correlation with neuropsychological tests and delayed recovery.

Mild traumatic brain injury (MTBI) is a common reason for hospital attendance and is associated with significant delayed morbidity. We studied a series of 80 persons with MTBI. Magnetic resonance imaging (MRI) and neuropsychological testing were used in the acute phase and a questionnaire for post-concussion syndrome (PCS) and return to work status at 6 months. In 26 subjects abnormalities were seen on MRI, of which 5 were definitely traumatic. There was weak correlation with abnormal neuropsychological tests for attention in the acute period. There was no significant correlation with a questionnaire for PCS and return to work status. Although non-specific abnormalities are frequently seen, standard MRI techniques are not helpful in identifying patients with MTBI who are likely to have delayed recovery.

Adult↗

PubMed2002

A graphical sensitivity analysis for clinical trials with non-ignorable missing binary outcome.

Many clinical trials are analysed using an intention-to-treat (ITT) approach. A full application of the ITT approach is only possible when complete outcome data are available for all randomized subjects. In a recent survey of clinical trial reports including an ITT analysis, complete case analysis (excluding all patients with a missing response) was common. This does not comply with the basic principles of ITT since not all randomized subjects are included in the analysis. Analyses of data with missing values are based on untestable assumptions, and so sensitivity analysis presenting a range of estimates under alternative assumptions about the missing-data mechanism is recommended. For binary outcome, extreme case analysis has been suggested as a simple form of sensitivity analysis, but this is rarely conclusive. A graphical sensitivity analysis is proposed which displays the results of all possible allocations of cases with missing binary outcome. Extension to allow binomial variation in outcome is also considered. The display is based on easily interpretable parameters and allows informal examination of the effects of varying prior beliefs.

Angioplasty, Balloon, Coronary↗

PubMed2002

Prediction of cardiac risk before abdominal aortic reconstruction: comparison of a revised Goldman Cardiac Risk Index and radioisotope ejection fraction.

BACKGROUND: A revised Goldman Cardiac Risk Index has been suggested to identify patients at higher risk for cardiac complications in patients who undergo major noncardiac surgery. The aim of this study was to test the usefulness of this model in an independent series of patients who underwent abdominal aortic surgery and to compare the index with the multiple gated acquisition (MUGA) scan in the prediction of cardiac complications. METHODS: We studied 77 patients who underwent MUGA scan before elective abdominal aortic reconstruction. The revised index was calculated for each patient after recording the following five risk factors: history of ischemic heart disease, congestive heart failure, cerebrovascular disease, insulin-dependent diabetes, and creatinine level more than 2 mg/dL. Technetium-99m MUGA scan provided information about the resting left ventricular ejection fraction (LVEF) and the presence of regional wall motion abnormalities. RESULTS: Fourteen patients (18%) had cardiac complications develop. The index proved to be a satisfactory predictor of postoperative cardiac events (P =.008), and an abnormal LVEF failed to do so (P =.1). The presence of wall abnormalities, with or without an abnormal LVEF, predicted cardiac complications (P =.004 and P =.006). Patients with a higher index score showed a tendency to have a lower LVEF (Spearman rank correlation, r = -0.43; P <.001). Wall abnormalities, with or without an abnormal LVEF, were more frequent in patients with higher scores (P =.03 and P =.009). Combining the index with the LVEF or the wall abnormalities or both could further stratify the cardiac risk (P =.004, P =.0003 and P =.0006, with chi(2) test for trend). CONCLUSION: For those patients who undergo elective abdominal aortic surgery, the revised Goldman Cardiac Risk Index is a simple method of evaluating cardiac risk with minimum resource implications. MUGA scan can offer additional stratification in patients judged with the index to be at high risk.

Aged↗