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Biomedical subjects

I McDowell

Publications and source records attributed to I McDowell.

At least 55 records · Page 3Linked to original sources
PubMed1995

Use of radiography in acute knee injuries: need for clinical decision rules.

OBJECTIVES: To study: 1) the efficiency of the current use of radiography in acute knee injuries, 2) the judgments and attitudes of experienced clinicians in their use of knee radiography, and 3) the potential for decision rules to improve efficiency. METHODS: This two-stage study of adults with acute knee injuries involved: 1) a retrospective review of all 1,967 patients seen over a 12-month period in the EDs of one community and two teaching hospital, and 2) a prospective survey of another 1,040 patients seen by attending emergency physicians. The prospective survey assessed each clinician's estimate of the probability of a knee or patella fracture; 120 patients were independently assessed by two physicians. RESULTS: Of the 1,967 patients seen in the first stage, 74.1% underwent radiography but only 5.2% were found to have fractures. Of the 1,727 knee and patella radiographic series ordered, 92.4% were negative for fracture. In the second stage, experienced physicians predicted the probability of fracture to be 0 or 0.1 for 75.6% of the patients. The kappa value for this response was 0.51 (95% CI 0.34 to 0.68). The physicians also indicated that they would have been comfortable or very comfortable in not ordering radiography for 55.5% of the patients. The area under the receiver operating characteristics curve for the physicians' prediction of fracture was 0.87 (95% CI 0.82 to 0.91), reflecting good discrimination between fracture and nonfracture cases. Likelihood ratios for the physicians' prediction ranged from 0.09 at the 0 level to 42.9 at the 0.9-1.0 level. CONCLUSIONS: Emergency physicians order radiography for most patients with acute knee injuries, even though they can accurately discriminate between fracture and nonfracture cases and expect most of the radiographs to be normal. These findings suggest great potential for more efficient use of knee radiography, possibly through the use of a clinical decision rule.

Adolescent↗
PubMed1994

Implementation of the Ottawa ankle rules.

OBJECTIVE: To assess the impact on clinical practice of implementing the Ottawa ankle rules. DESIGN: Nonrandomized, controlled trial with before-after and concurrent controls. SETTING: Emergency departments of a university (intervention) hospital and a community (control) hospital. PATIENTS: All 2342 adults seen with acute ankle injuries during 5-month periods before and after the intervention. INTERVENTION: The implementation of the Ottawa ankle rules by emergency department physicians. MAIN OUTCOME MEASURE: Proportions of patients referred for standard ankle and foot radiographic series. RESULTS: There was a relative reduction in ankle radiography by 28% at the intervention hospital but an increase by 2% at the control hospital (P < .001). Foot radiography was reduced by 14% at the intervention hospital but increased by 13% at the control hospital (P < .05). Compared with nonfracture patients who had radiography during the after period at the intervention hospital, those discharged without radiography spent less time in the emergency department (80 minutes vs 116 minutes; P < .0001), had lower estimated total medical costs for physician visits and radiography ($62 vs $173; P < .001), but did not differ in the proportion satisfied with emergency physician care (95% vs 96%) or undergoing subsequent radiography (5% vs 5%). The rules were found to have sensitivities of 1.0 (95% confidence interval [CI], 0.95 to 1.0) for detecting 74 malleolar fractures and 1.0 (95% CI, 0.82 to 1.0) for detecting 19 midfoot fractures. In the following 12 months at the intervention hospital, use of radiography did not increase. CONCLUSIONS: Implementation of the Ottawa ankle rules led to a decrease in use of ankle radiography, waiting times, and costs without patient dissatisfaction or missed fractures. Future studies should address the generalizability of these decision rules in a variety of hospital settings.

Adult↗
PubMed1993

Decision rules for the use of radiography in acute ankle injuries. Refinement and prospective validation.

OBJECTIVE: To validate and refine previously derived clinical decision rules that aid the efficient use of radiography in acute ankle injuries. DESIGN: Survey prospectively administered in two stages: validation and refinement of the original rules (first stage) and validation of the refined rules (second stage). SETTING: Emergency departments of two university hospitals. PATIENTS: Convenience sample of adults with acute ankle injuries: 1032 of 1130 eligible patients in the first stage and 453 of 530 eligible patients in the second stage. MAIN OUTCOME MEASURES: Attending emergency physicians assessed each patient for standardized clinical variables and classified the need for radiography according to the original (first stage) and the refined (second stage) decision rules. The decision rules were assessed for their ability to correctly identify the criterion standard of fractures on ankle and foot radiographic series. The original decision rules were refined by univariate and recursive partitioning analyses. MAIN RESULTS: In the first stage, the original decision rules were found to have sensitivities of 1.0 (95% confidence interval [CI], 0.97 to 1.0) for detecting 121 maleolar zone fractures, and 0.98 (95% CI, 0.88 to 1.0) for detecting 49 midfoot zone fractures. For interpretation of the rules in 116 patients, kappa values were 0.56 for the ankle series rule and 0.69 for the foot series rule. Recursive partitioning of 20 predictor variables yielded refined decision rules for ankle and foot radiographic series. In the second stage, the refined rules proved to have sensitivities of 1.0 (95% CI, 0.93 to 1.0) for 50 malleolar zone fractures, and 1.0 (95% CI, 0.83 to 1.0) for 19 midfoot zone fractures. The potential reduction in radiography is estimated to be 34% for the ankle series and 30% for the foot series. The probability of fracture, if the corresponding decision rule were "negative," is estimated to be 0% (95% CI, 0% to 0.8%) in the ankle series, and 0% (95% CI, 0% to 0.4%) in the foot series. CONCLUSION: Refinement and validation have shown the Ottawa ankle rules to be 100% sensitive for fractures, to be reliable, and to have the potential to allow physicians to safely reduce the number of radiographs ordered in patients with ankle injuries by one third. Field trials will assess the feasibility of implementing these rules into clinical practice.

Adolescent↗
PubMed1993

Stress responses after treatment of hypercholesterolaemia with simvastatin.

In order to determine whether treatment of hyperlipidaemia with simvastatin impairs exercise stress responses and so may contribute to an excess of suicides and violent deaths, the effects of simvastatin 20 mg daily and placebo on exercise physiology were compared in 19 patients. After 6 weeks of treatment there was no evidence of reduced exercise capacity, or of reduced cortisol or catecholamine responses. It is concluded that treatment of hyperlipidaemia with an inhibitor of HMG-CoA reductase does not significantly modify stress responses, and so the explanation for a possible increase in non-cardiac mortality must be sought elsewhere.

Adrenocorticotropic Hormone↗
PubMed1992

Use of radiography in acute ankle injuries: physicians' attitudes and practice.

OBJECTIVES: To examine the efficiency of the current use of radiography in patients with acute ankle injury. To study the judgements and attitudes of experienced clinicians in their use of ankle radiography and to thereby assess the potential for improved efficiency. DESIGN: Two-stage study: retrospective chart review and prospective survey. SETTING: Emergency departments of two adult teaching hospitals and one community hospital. PARTICIPANTS: The records of 1831 adults presenting with acute blunt trauma to the ankle over 5 months were examined; another 732 patients were seen by 21 full-time emergency staff physicians over a subsequent 6-month period. MEASURES AND MAIN RESULTS: Of the 1831 patients with an ankle injury in stage 1, 94.9% had had at least one radiographic series; the yield for clinically important fractures was 12.8%. In stage 2, experienced physicians predicted the probability of fracture to be 0% or 10% in 57.8% of cases. The kappa (kappa) level for interobserver agreement in 98 patients seen independently by two physicians was 0.55 (95% confidence interval [CI] 0.39 to 0.72). The area under the receiver operating characteristic curve for physicians' predicted probability was 0.88 (95% CI 0.84 to 0.92), reflecting good discrimination between fracture and nonfracture cases. Likelihood ratios for predicted probabilities ranged from 0.08 for the 0% level to 151 for the 100% level. The physicians indicated that they would feel comfortable or very comfortable in not ordering radiography in 45.9% of cases (kappa level 0.52; 95% CI 0.34 to 0.70). CONCLUSIONS: Emergency physicians order radiography for most patients with ankle injury even though they can accurately discriminate between fracture and nonfracture cases and clearly expect most of the radiographs to give normal results. These findings suggest great potential for a more efficient use of radiography in patients with ankle injury, possibly through the use of guidelines.

Adult↗
PubMed1992

Use of reminders to increase compliance with tetanus booster vaccination.

OBJECTIVE: To assess the effect of three computerized reminder systems on compliance with tetanus vaccination. DESIGN: Prospective randomized controlled trial. SETTING: Ottawa Civic Hospital Family Medicine Centre. PARTICIPANTS: Of 8069 patients 20 years of age or more who were not in a hospital or institution 5589 were randomly assigned, by family, to a control group, a physician reminder group, a telephone reminder group or a letter reminder group. The remaining 2480 patients were not included in the randomized portion of the study but were monitored. Results are presented for the 5242 randomized patients and the 2369 nonrandomized patients for whom there was no up-to-date record of tetanus vaccination at the start of the trial. INTERVENTIONS: For the patients in the physician reminder group the physician was reminded at an office visit to assess the patient's tetanus vaccination status and to recommend vaccination; those in the other two reminder groups received a telephone call or letter enquiring about their tetanus vaccination status and recommending a booster dose. MAIN OUTCOME MEASURE: Proportion of patients who received tetanus toxoid during the study year or who had a claim of vaccination in the previous 10 years. MAIN RESULTS: The rate of recorded tetanus vaccination in the randomized control group was 3.2%. The difference between that rate and those for the three reminder groups was 19.6% in the physician reminder group (95% confidence interval [CI] 17.1% to 22.2%, p less than 0.00001), 20.8% in the telephone reminder group (95% CI 18.3% to 23.5%, p less than 0.00001) and 27.4% in the letter reminder group (95% CI 24.8% to 30.2%, p less than 0.00001)). The letter reminders were more effective than either the telephone reminders (p = 0.00013) or the physician reminders (p less than 0.00001) in improving compliance. The cost to the practice per additional vaccination recorded was 43 for the physician reminders, $5.43 for the telephone reminders and $6.05 for the letter reminders. CONCLUSIONS: Although all three reminder systems increased the rate of recorded tetanus vaccination they fell far short of achieving complete population coverage. More intensive interventions would be required to approach that goal. However, such interventions do not appear to be justified given the rarity of tetanus.

Adult↗
PubMed1992

Interobserver agreement in the examination of acute ankle injury patients.

The authors' objective was to describe a method for measuring interobserver agreement and to determine the reliability of physical findings used by emergency physicians to assess ankle injury patients. A 3-month prospective survey was designed for use in the emergency departments of two university hospitals. Participants were a convenience sample of 100 adult blunt ankle injury patients. Pairs of emergency staff physicians assessed 22 standardized physical findings in each patient without knowledge of the other assessment. Agreement for each variable was measured by the kappa coefficient, the ratio of actual agreement to potential agreement beyond chance. The variables with the highest interobserver agreement and their kappa values were ability to bear weight (.83); bone tenderness at the base of the fifth metatarsal (.78), at the posterior edge of lateral malleolus (.75), and at the tip of the medial malleolus (.66); and combinations of bone tenderness (.76). Less reliable variables included soft tissue tenderness (.41) or degree of swelling (.18) of the anterior talofibular ligament, ecchymosis (.39), range of motion (.33), bone tenderness at the proximal fibula (-.01), and the anterior drawer sign (-.03). High kappa values indicate that several physical findings, including ability to bear weight and selected sites of bone tenderness, may be reliably assessed in ankle injury patients. This knowledge may give physicians more confidence in their physical examination and allow development of reliable clinical guidelines to diminish the reliance on radiography in ankle injuries.

Adult↗
PubMed1992

A study to develop clinical decision rules for the use of radiography in acute ankle injuries.

STUDY OBJECTIVE: To develop decision rules that will predict fractures in patients with ankle injuries, thereby assisting clinicians in being more selective in their use of radiography. DESIGN: Prospective survey of emergency department patients over a five-month period. SETTING: Two university hospital EDs. PARTICIPANTS: One hundred fifty-five adults in a pilot stage and 750 in the main study; all presented with acute blunt ankle injuries. INTERVENTIONS: Thirty-two standardized clinical variables were assessed and recorded on data sheets by staff emergency physicians before radiography. MEASUREMENTS: Variables were assessed for reliability by the kappa coefficient and for association with significant fracture on both ankle and foot radiographic series by univariate analysis. The data then were analyzed by logistic regression and recursive partitioning techniques to develop decision rules for predicting fractures in each radiographic series. MAIN RESULTS: All 70 significant malleolar fractures found in the 689 ankle radiographic series performed were identified among people who had pain near the malleoli and were age 55 years or more, had localized bone tenderness of the posterior edge or tip of either malleolus, or were unable to bear weight both immediately after the injury and in the ED. This rule was 100% sensitive and 40.1% specific for detecting malleolar fractures and would allow a reduction of 36.0% of ankle radiographic series ordered. Similarly, all 32 significant midfoot fractures on the 230 foot radiographic series performed were found among patients with pain in the midfoot and bone tenderness at the base of the fifth metatarsal, the cuboid, or the navicular. CONCLUSION: Highly sensitive decision rules have been developed and will now be validated; these may permit clinicians to confidently reduce the number of radiographs ordered in patients with ankle injuries.

Adult↗
PubMed1991

Use of reminders for preventive procedures in family medicine.

OBJECTIVE: To compare the effectiveness of three computerized reminder systems in the delivery of five preventive procedures in family practice. DESIGN: Prospective, randomized, controlled study. SETTING: Ottawa Civic Hospital Family Medicine Centre. PARTICIPANTS: Of 8502 patients 15 years of age or more who were not in a hospital or institution 5883 were randomly assigned, by family, to a control group, a physician reminder group (passive) or a telephone or letter reminder group (active). The remaining 2619 patients were not included in the randomized portion of the study but were monitored. INTERVENTION: During 1 year the patients in the active reminder groups received a telephone call or letter reminding them of any overdue preventive procedures; for those in the passive reminder group the physician was reminded at an office visit to provide any overdue service. OUTCOME MEASURE: Rates of completion of the preventive procedures required. MAIN RESULTS: All three reminder systems significantly improved the delivery of preventive services (p less than 0.001). The procedure completion rates were 42.0% in the letter reminder group, 42.0% in the telephone reminder group, 33.7% in the physician reminder group and 14.1% in the randomized control group. The use of a letter was more cost-effective than the telephone system, but the physician reminder system was the most cost-effective. CONCLUSION: Computerized reminder systems do improve the delivery of preventive services in family practice.

Adolescent↗
PubMed1990

Canadian Study of Health and Aging (CaSHA).

A Canada-wide study of the epidemiology of dementias was initiated in the summer of 1990 with the support of Health and Welfare Canada. The four objectives are to estimate the prevalence of dementias among elderly Canadian citizens, to determine the risk factors for dementia of the Alzheimer type, to describe the current pattern of caring for demented patients and assess the burden on informal caregivers, and to establish a uniform database for future incidence and longitudinal studies of dementias. Trained interviewers will screen a representative sample of senior citizens in the community. The screening is followed by a standardized clinical assessment for putative cases of dementia, for institutionalized patients and for a number of controls. Diagnosis will follow DSM-III-R criteria for dementia, the NINCDS-ADRDA criteria for dementia of the Alzheimer type and the ICD-10 criteria for other dementias. A sample of cases and controls will then enter the caregiver and risk factor sub-studies.

Aged↗
PubMed1989

A randomized trial of computerized reminders for blood pressure screening in primary care.

In a randomized, controlled trial (N = 8,298) the authors compared three ways of encouraging patients in a large family practice to obtain a blood pressure check. Working from computerized medical records at a teaching family-medicine center, the study included patients aged 18 years and over who had not had a blood pressure measurement during the previous year. In a normal-care control group, 21.1% of those due for a blood pressure reading obtained one during the trial year. In one intervention group, a computer-generated message reminded the doctor to check the blood pressure of patients who happened to visit the center for an appointment; 30.7% of patients allocated to this group were checked. In the second group, the nurse contacted patients by telephone and encouraged 24.1% of those who were due for a check to obtain one. Sending a letter to patients in the third group yielded a 35.7% compliance rate. Considering the costs of the three interventions, the physician reminder was the most cost effective, followed by the letter reminder. Although statistically significant, the impact of the reminders was modest. A better approach might involve a combination of routine reminders to the physician, followed by letters to noncompliant patients.

Adolescent↗
PubMed1989

Computerized reminders to encourage cervical screening in family practice.

In a randomized trial three ways of increasing rates of cervical screening were compared for women attending a family medicine center. Working from computerized medical records, 1,587 women aged 18 to 35 years who were overdue for a screening test were included in the study. In a control group, no formal method was used to encourage patients to attend for screening, and 13.7 percent obtained a test within the trial year. In one intervention group the physician was issued a message identifying those women visiting the center for a routine appointment who were due for screening; 16.1 percent were screened. Sending a letter to patients in a second group yielded a 25.9 percent compliance rate. In a third group the practice nurse called patients on the telephone to advise them to obtain the test, and 20.0 percent complied. Reminders issued to the physician provide a low-cost, opportunistic approach to reach women who happen to visit the practice, but this approach should be supplemented by telephoning or sending a letter to those women who do not attend regularly.

Adolescent↗
PubMed1988

Subject characteristics and long term post-program smoking cessation.

In order to identify predictors of long-term post-treatment smoking abstinence, 333 adult smokers who volunteered to participate in a smoking cessation program were asked to complete a set of questionnaires which measured self-efficacy, motivation, reasons for smoking, and smoking history variables. Subjects were then randomly assigned to one of four smoking cessation interventions. Nine variables predicted abstinance up to and including one year following treatment. The importance of self-efficacy beliefs in quitting smoking was underscored.

Adult↗
PubMed1987

Screening for psychosocial problems among primary care patients: a pilot study.

The symptoms that a patient presents to the doctor are often not the underlying concern that prompted the consultation. The success of consultations involving a hidden diagnosis depends on how well the patient can express his or her concerns to the doctor and on how skilfully the doctor can encourage this. This study tested the feasibility and acceptability of having patients complete a brief health index questionnaire designed to help them describe their underlying concerns to the doctor. In two family medicine centres 996 patients were asked to complete a questionnaire while waiting to see the doctor; 724 (73%) did so. An evaluation of their responses showed the method to be acceptable to most. The doctors judged that it added valuable information in 41% of all consultations and in 73% of consultations in which the patient presented with psychologic complaints. There was, nevertheless, considerable variation among the physicians in their acceptance of the approach. This variability is discussed in the light of alternative models of how, in practical terms, to treat the psychosocial dimensions of a patient's complaint.

Adult↗
PubMed1986

Comparison of three methods of recalling patients for influenza vaccination.

Despite recommendations supporting annual influenza vaccination for people aged 65 years or older, vaccination rates remain low. Several studies have evaluated the effect of sending mailed reminders, but few have compared alternative ways of reminding patients to receive the vaccine. In a randomized trial of 939 patients aged 65 years or older in four family practices carried out between Oct. 23 and Dec. 31, 1984, we compared three ways of reminding elderly patients to receive the vaccine: personal reminder by the physician, telephone reminder by the nurse and reminder by letter. The vaccination rates for the three groups were 22.9%, 37% and 35.1% respectively. No reminder was issued to a control group, and the rate was 9.8%. Some patients could not be reached by telephone, and some did not see the physician during the specified time. Among the patients whom the nurse actually contacted, the vaccination rate was 43.5%; the rate for patients whom the doctor actually saw was 45.1%. Overall, a telephone reminder by the nurse was the most effective method, and at an hourly salary of $16 or less this method would also be the most cost-effective. The reminders used in this study were automatically generated from a computerized medical record system. The study shows how a computerized system can be used to identify patients for whom preventive procedures are due.

Aged↗