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D A Redelmeier

Publications and source records attributed to D A Redelmeier.

At least 55 records · Page 3Linked to original sources
PubMed1998

Measuring injury severity: time for a change?

BACKGROUND: The Injury Severity Score (ISS) does not take into account multiple injuries in the same body region, whereas a New ISS (NISS) may provide a more accurate measure of trauma severity by considering the patient's three greatest injuries regardless of body region. The purpose of this study was to evaluate the ISS and NISS in patients with blunt trauma. METHODS: Consecutive individuals treated from January of 1992 to September of 1996 at one institution were included if they had sustained blunt trauma and satisfied triage standards (n = 2,328). For each patient, we computed the ISS and the NISS to determine how often the two scores were identical or discrepant. Discrepant cases were then further analyzed using receiver operating characteristic curves to determine which score better predicted short-term mortality. RESULTS: The mean ISS was 25 +/- 13, and the mean NISS was 33 +/- 18. The two predictive scores were identical in 32% of patients and discrepant in 68% of patients. Patients with identical scores had a lower mortality rate than patients with discrepant scores (10% vs. 13%; p < 0.02). In patients with discrepant scores, the area under the receiver operating characteristic curves was greater for the NISS than the ISS (0.852 vs. 0.799; p < 0.001), and greater amounts of discrepancy were associated with increasing rates of mortality (p < 0.001). CONCLUSIONS: The NISS often increases the apparent severity of injury and provides a more accurate prediction of short-term mortality. The benefit associated with using the NISS rather than the ISS must be weighed against the disadvantages of changing a scoring system and the potential for still greater improvements.

Abbreviated Injury Scale↗
PubMed1998

Improved diagnostic accuracy of inferior petrosal sinus sampling over imaging for localizing pituitary pathology in patients with Cushing's disease.

The majority of patients with Cushing's disease can be cured by transsphenoidal microsurgery; however, precise localization of the pituitary source of ACTH is not always possible by standard imaging techniques. Bilateral venous sampling from the inferior petrosal sinuses (IPSS) is also useful for diagnosing Cushing's disease, but the interpretation of discordant findings between IPSS and imaging remains problematic. We tested the ability of imaging and IPSS to localize an ACTH-secreting pituitary lesion in comparison to definitive histopathological examination of the pituitary in patients with Cushing's disease (n = 37). Bilateral IPS catheterization was technically feasible in 32 patients and provided evidence of lateralization in 31 patients. Histological examination confirmed a corticotropic adenoma in 28 patients and corticotropic hyperplasia in 2 patients; Crooke's hyaline change was found in 7 patients, among whom 1 subsequently was found to have an ectopic sphenoid corticotropic adenoma, and the remainder had suspected microadenomas that were not identified microscopically. Accurate localization of the pituitary lesion was more frequent when based on IPSS results than on imaging studies (70% vs. 49%, P < 0.06). The 2 tests provided directly discrepant results for 8 patients; among these, IPSS was more likely than imaging to agree with final pathology (63% vs. 13%, P < 0.10). Imaging was entirely normal for another 9 patients, in whom IPSS accurately localized the lesion for the majority (89%; 95% confidence interval: 50-99%). We suggest that IPSS is an effective tool for localizing pituitary pathology and planning surgery for patients with Cushing's disease.

Adrenocorticotropic Hormone↗
PubMed1997

Association between cellular-telephone calls and motor vehicle collisions.

BACKGROUND: Because of a belief that the use of cellular telephones while driving may cause collisions, several countries have restricted their use in motor vehicles, and others are considering such regulations. We used an epidemiologic method, the case-crossover design, to study whether using a cellular telephone while driving increases the risk of a motor vehicle collision. METHODS: We studied 699 drivers who had cellular telephones and who were involved in motor vehicle collisions resulting in substantial property damage but no personal injury. Each person's cellular-telephone calls on the day of the collision and during the previous week were analyzed through the use of detailed billing records. RESULTS: A total of 26,798 cellular-telephone calls were made during the 14-month study period. The risk of a collision when using a cellular telephone was four times higher than the risk when a cellular telephone was not being used (relative risk, 4.3; 95 percent confidence interval, 3.0 to 6.5). The relative risk was similar for drivers who differed in personal characteristics such as age and driving experience; calls close to the time of the collision were particularly hazardous (relative risk, 4.8 for calls placed within 5 minutes of the accident, as compared with 1.3 for calls placed more than 15 minutes before the accident; P<0.001); and units that allowed the hands to be free (relative risk, 5.9) offered no safety advantage over hand-held units (relative risk, 3.9; P not significant). Thirty-nine percent of the drivers called emergency services after the collision, suggesting that having a cellular telephone may have had advantages in the aftermath of an event. CONCLUSIONS: The use of cellular telephones in motor vehicles is associated with a quadrupling of the risk of a collision during the brief time interval involving a call. Decisions about regulation of such telephones, however, need to take into account the benefits of the technology and the role of individual responsibility.

Accidents, Traffic↗
PubMed1997

Interpretation and bias in case-crossover studies.

The case-crossover design is an innovative epidemiologic technique with distinct strengths and limitations. We review the fundamental logic of this self-matching non-randomized design and direct attention to 15 concerns related to the available data, unavailable data, analytic technique, quantitative statistics, and etiologic model. Implications for each concern are discussed in the context of a recent report on whether cellular telephone calls are associated with an increased risk of a motor vehicle collision. We suggest that an understanding of the case-crossover design may help investigators explore selected questions in behavioral medical research.

Bias↗
PubMed1997

Long-term outcomes in open pelvic fractures.

BACKGROUND: Open pelvic fractures represent one of the most devastating injuries in orthopedic trauma. The purpose of this study was to document the injury characteristics, complications, mortality, and long-term, health-related quality of life outcomes in patients with open pelvic fractures. METHODS: The trauma registry at an adult trauma center was used to identify all multiple system blunt trauma patients with a pelvic fracture from January of 1987 to August of 1995 (n = 1,179). Demographic data, mechanism of injury, and fracture type were determined from hospital records. Short-term outcome measures included infectious complications, mortality, and length of stay in hospital. Long-term outcomes of survivors were obtained by telephone interview using the SF-36 Health Survey and the Functional Independence Measure. RESULTS: Open pelvic fractures were uncommon, occurring in 44 patients (4%). Patients with open fractures were about 9 years younger, on average, than patients with closed fractures (30 vs. 39, p < 0.001). Similarly, patients with open fractures were more likely to be male (75 vs. 57%, p < 0.02), more likely to have been involved in a motorcycle crash (27 vs. 6%, p < 0.001), and more likely to have an unstable pelvic ring disruption (45 vs. 25%, p < 0.001). Open pelvic fracture patients required more blood than closed pelvic fracture patients, both in the first day (16 vs. 4 units, p < 0.001) and during the total hospital admission (29 vs. 9 units, p < 0.001). Five patients with perineal wounds did not receive a diverting colostomy; in turn, these individuals had a total of six pelvic infectious complications (one abscess, two with osteomyelitis, and three perineal wound infections). Overall, 11 patients died, six patients were lost to follow-up, and 27 were long-term survivors (mean duration of 4 years). Chronic disability was common after a pelvic fracture, with problems related to physical role performance and physical functioning, and was particularly severe after an open pelvic fracture (p < 0.05 for both as measured by the SF-36). CONCLUSIONS: Patients with open pelvic fractures often survive, need to be treated with massive blood transfusions, and often require a colostomy. They are frequently left with chronic pain and residual disabilities in physical functioning and physical roles, and many remain unemployed years after injury.

Activities of Daily Living↗
PubMed1997

Long-term outcomes in blunt trauma: who goes back to work?

BACKGROUND: Trauma patients continue to improve after discharge from the trauma center, but the completeness of this recovery remains uncertain. The purpose of this study was to compare the characteristics of patients who do and who do not return to work after blunt trauma. METHODS: Consecutive survivors of blunt trauma discharged from a regional trauma center over a 1-year interval (July of 1994 to June of 1995) were included in the study. Patients completed the SF-36 Health Survey and some additional questions related to employment status both at discharge and again after 1 year. Our principal analysis compared patients who were employed and unemployed at 1-year follow-up. RESULTS: Complete data were available for 195 patients. The typical patient was a young man who had been in a motor vehicle collision and had an injury severity score of 25. At 1-year follow-up, 101 patients had returned to work and 94 remained unemployed. Employed individuals were younger (31 vs. 44 years, p < 0.0001), less severely injured (mean injury severity score 23 vs. 27, p < 0.001), and more likely to hold professional jobs (50 vs. 16%, p < 0.0001). Patterns of injury and operative procedures were similar for employed and unemployed patients. However, the average employed patient had fewer days in the intensive care unit (2 vs. 5 days, p < 0.001), a shorter total hospitalization (19 vs. 28 days, p < 0.01), and was more likely to be discharged to home (62 vs. 39%, p < 0.01). At discharge, those who went on to employment had marginally better SF-36 Health Survey scores on seven of the eight scales (all except general health). During the year after discharge, both groups improved significantly, although employed individuals to a greater extent on all scales of the SF-36 Health Survey. CONCLUSIONS: Almost one half of the multiple system blunt trauma patients remain unemployed 1 year after hospital discharge. Those patients who return to work are usually young professionals with a lower severity of injury. Functional status at discharge predicts future employment status, but underestimates the extent of long-term recovery.

Absenteeism↗
PubMed1997

Interpreting small differences in functional status: the Six Minute Walk test in chronic lung disease patients.

Functional status measurements are often difficult to interpret because small differences may be statistically significant but not clinically significant. How much does the Six Minute Walk test (6MW) need to differ to signify a noticeable difference in walking ability for patients with chronic obstructive pulmonary disease (COPD)? We studied individuals with stable COPD (n = 112, mean age = 67 yr, mean FEV1 = 975 ml) and estimated the smallest difference in 6MW distances that was associated with a noticeable difference in patients' subjective comparison ratings of their walking ability. We found that the 6MW was significantly correlated with patients' ratings of their walking ability relative to other patients (r = 0.59, 95% confidence interval [CI]: 0.54 to 0.63). Distances needed to differ by 54 m for the average patient to stop rating themselves as "about the same" and start rating themselves as either "a little bit better" or "a little bit worse" (95% CI: 37 to 71 m). We suggest that differences in functional status can be statistically significant but below the threshold at which patients notice a difference in themselves relative to others; an awareness of the smallest difference in walking distance that is noticeable to patients may help clinicians interpret the effectiveness of symptomatic treatments for COPD.

Aged↗
PubMed1996

On the belief that arthritis pain is related to the weather.

There is a widespread and strongly held belief that arthritis pain is influenced by the weather; however, scientific studies have found no consistent association. We hypothesize that this belief results, in part at least, from people's tendency to perceive patterns where none exist. We studied patients (n = 18) for more than I year and found no statistically significant associations between their arthritis pain and the weather conditions implicated by each individual. We also found that college students (n = 97) tend to perceive correlations between uncorrelated random sequences. This departure of people's intuitive notion of association from the statistical concept of association, we suggest, contributes to the belief that arthritis pain is influenced by the weather.

Arthritis, Rheumatoid↗
PubMed1996

Assessing the minimal important difference in symptoms: a comparison of two techniques.

We have developed a method for estimating the minimally important difference (MID) for health status measures. Whereas the conventional approach requires patients to judge themselves relative to their memories, our method requires patients to judge themselves relative to others with the same condition. In this study we examined whether our method (based on between-patient differences) and the conventional method (based on within-patient changes) provides comparable estimates of the MID for one health status measure: the Chronic Respiratory Questionnaire. Patients with chronic obstructive pulmonary disease who were participating in a supervised respiratory rehabilitation program were included if they were in stable health (n = 112). Their mean score per question in the Chronic Respiratory Questionnaire was 4.5 (range, 1 to 7; where bigger values indicate better health). Our method estimated that the MID was 0.5 (95% confidence interval 0.4 to 0.7). This estimate was similar to the MID previously found using the conventional method. These observations support the role of the Chronic Respiratory Questionnaire for measuring patient's symptoms, the validity of our approach for assessing the MID, and an estimate on the order of 0.5 as the threshold for this particular health status measure.

Adaptation, Psychological↗
PubMed1996

Spirometry and dyspnea in patients with COPD. When small differences mean little.

OBJECTIVE: To determine when a difference in FEV1 is sufficiently large to be associated with a noticeable difference in dyspnea symptoms for patients with chronic lung disease. DESIGN: Cross-sectional analysis of 15 groups (n = 112 patients, 832 contrasts). SETTING: Respiratory rehabilitation program. PATIENTS: Patients with COPD (mean FEV1 = 35% predicted). MEASURES: Patients' perspectives assessed through subjective comparison ratings of dyspnea and of overall health. Relation between the FEV1 and patients' perspectives determined the smallest difference in spirometry that was associated with a noticeable difference in patients' symptoms. RESULTS: The FEV1 was moderately correlated with patients' ratings of dyspnea (r = 0.29; 95% confidence interval (CI), 0.22 to 0.35). In contrast, the FEV1 was minimally correlated with patients' ratings of overall health (r = 0.10; 95% CI, 0.03 to 0.17). The FEV1 needed to differ by 4% predicted for the average patient to stop rating his or her dyspnea as "about the same" and start rating his or her dyspnea as either "a little bit better" or "a little bit worse" relative to other patients (95% CI, 1.5 to 6.5). This was equivalent to the average patient's FEV1 increasing by 112 mL (starting from 975 mL and ending at 1,087 mL). CONCLUSIONS: Some statistically significant differences in the FEV1 are so small that they may not represent important differences in symptoms for the average patient with severe COPD; an awareness of the smallest difference in FEV1 that is noticeable to patients can help clinicians interpret the effectiveness of symptomatic treatments.

Aged↗
PubMed1995

A randomised trial of compassionate care for the homeless in an emergency department.

Homeless adults often visit emergency departments and often leave dissatisfied. We tested whether compassionate care, by improving patient satisfaction, can alter subsequent use of emergency services. We identified 133 consecutive homeless adults visiting one inner-city emergency department who were not acutely psychotic, extremely intoxicated, unable to speak English, or medically unstable. Half were randomly assigned to receive compassionate contact from trained volunteers. All patients otherwise had usual care and were followed for repeat visits to emergency departments. We found that rates of use were high, with patients making an average of seven visits a year (0.60 per month). More than a third of all patients made two or more visits within two days of each other. The average number of visits per month after intervention was significantly lower for patients who received compassionate care (0.43 vs 0.65, p = 0.018). Analyses adjusting for each patient's previous rate of use confirmed that compassionate care led to a one third reduction in the number of return visits within one month (95% CI 14 to 40%). Compassionate management of selected homeless adults decreases repeat visits to the emergency department. One explanation is that patients tend to return frequently until they are satisfied with their treatment.

Adult↗
PubMed1995

Medical decision making in situations that offer multiple alternatives.

OBJECTIVE: To determine whether situations involving multiple options can paradoxically influence people to choose an option that would have been declined if fewer options were available. DESIGN: Mailed survey containing medical scenarios formulated in one of two versions. PARTICIPANTS: Two groups of physicians: members of the Ontario College of Family Physicians (response rate = 77%; n = 287) and neurologists and neurosurgeons affiliated with the North American Symptomatic Carotid Endarterectomy Trial (response rate = 84%; n = 352). One group of legislators belonging to the Ontario Provincial Parliament (response rate = 32%; n = 41). INTERVENTION: The basic version of each scenario presented a choice between two options. The expanded version presented three options: the original two plus a third. The two versions otherwise contained identical information and were randomly assigned. OUTCOME MEASURES: Participants treatment recommendations. RESULTS: In one scenario involving a patient with osteoarthritis, family physicians were less likely to prescribe a medication when deciding between two medications than when deciding about only one medication (53% vs 72%; P < .005). Apparently, the difficulty in deciding between the two medications led some physicians to recommend not starting either. Similar discrepancies were found in decisions made by neurologists and neurosurgeons concerning carotid artery surgery and by legislators concerning hospital closures. CONCLUSIONS: The introduction of additional options can increase decision difficulty and, hence, the tendency to choose a distinctive option or maintain the status quo. Awareness of this cognitive bias may lead to improved decision making in complex medical situations.

Bias↗
PubMed1995

A prospective multicenter octreotide dose response study in the treatment of acromegaly.

The somatostatin analog octreotide has proven to be an effective form of treatment for various hypersecretory states including acromegaly. This report describes the effects of escalating doses of octreotide on the growth hormone (GH) profiles, insulin-like growth factor-1 (IGF-1), prolactin (PRL), and adverse effects in 99 patients with acromegaly. Treatment with octreotide was initiated at 50 micrograms sc every 8 h and the dose gradually titrated to a maximum of 1500 micrograms/d if more than 75% of GH determinations in a 12-h day profile were above detection limits. This dose was maintained for the duration of 6 months. Seventy-three percent of patients did not reach the GH reduction criterion at the 300 micrograms dose. Mean GH levels decreased from 33 +/- 4 micrograms/l to 10 +/- 1 microgram/l (p < 0.001) while receiving the 300 micrograms/d dose. The percentage decrease in mean GH levels, however, was dose-independent reaching 50 +/- 5% of baseline with 300 micrograms/d, 55 +/- 5% with 600 micrograms/d, 57 +/- 6% with 900 micrograms/d, and 56 +/- 5% with 1500 micrograms/d. Maximal GH suppression, however, was achieved in 40%, 17%, 7%, and 16% of subjects by the 300 micrograms, 600 mg, 900 micrograms, and 1500 micrograms doses respectively. GH suppression was independent of duration of treatment. While there was a tendency for a greater degree of IGF-1 reduction with the higher doses, the rate of normalization (30-37%) was not influenced by the dose of octreotide administered. Elevated PRL levels also declined with the use of higher doses of octreotide.(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly↗
PubMed1995

Acute and long-term outcomes of extremely injured blunt trauma victims.

Long-term outcomes after blunt trauma remain poorly defined. The purpose of this study was to document such outcomes in extremely injured adults (Injury Severity Score > or = 50). From April 1990 to June 1993, 76 patients (5% of all trauma victims) had an ISS > or = 50 at a single trauma center. Thirty-five (46%) survived to hospital discharge. The mean duration of hospital stay was longer for survivors than for nonsurvivors (92 days versus 16 days, p < 0.001). Of the 35 survivors, 26% were discharged directly home, 60% to a rehabilitation hospital, 8% to a chronic care facility, and 6% to an acute care hospital. After a mean follow-up of 27 months, 6% had died, 9% refused participation, and the remaining 30 patients (91% of long-term survivors) demonstrated significant residual disabilities in physical, emotional, and mental health status. We suggest that extremely injured patients comprise a small proportion of blunt trauma victims, consume substantial acute care hospital resources, often survive, and yet frequently have residual disability. A reduction in this long-term disability may represent the greatest challenge in modern trauma care.

Adolescent↗
PubMed1995

In vivo responsiveness of morphological variants of growth hormone-producing pituitary adenomas to octreotide.

The somatostatin analog, octreotide, is an inhibitor of growth hormone (GH) secretion that has been used to treat patients with GH-producing pituitary tumors. In this study we investigated the in vivo responsiveness to treatment with this analog in patients harboring different morphological types of GH-producing pituitary adenomas. Both GH and insulin-like growth factor I (IGF-I) plasma levels in 30 patients treated with octreotide (300 micrograms/day) for 4 months preoperatively were compared with those from 30 patients who did not receive treatment preoperatively. Tissue samples were studied using ultrastructural and immunohistochemical techniques. Amongst patients harboring densely granulated (DG) adenomas, mean GH levels were reduced to 32 +/- 9% by octreotide, to 30 +/- 7% by surgery and to 26 +/- 9% of baseline by both interventions. Surgery was equally as effective in lowering GH levels in patients with sparsely granulated (SG) adenomas as it was in those with DG adenomas; in patients with SG adenomas, GH levels were reduced by surgery alone to 37 +/- 16% and to 24 +/- 15% when performed following octreotide pretreatment. In contrast, treatment with octreotide alone in patients harbouring SG adenomas reduced GH levels to only 70 +/- 13% of baseline (p < 0.02 compared to surgery alone, or surgery and octreotide). We conclude that the GH inhibitory effects of octreotide are significantly better in patients harboring DG somatotroph adenomas compared with those harboring SG adenomas.

Acromegaly↗