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Biomedical subjects

N E Mayo

Publications and source records attributed to N E Mayo.

At least 37 records · Page 2Linked to original sources
PubMed1995

Rates of transcervical and pertrochanteric hip fractures in the province of Quebec, Canada, 1981-1992.

Two distinct subtypes of hip fracture, transcervical and pertrochanteric, can be distinguished on the basis of the anatomical location of the injury. While the epidemiology of hip fractures has been well described, typically, little or no distinction is made between these subtypes. The objective of this study was to compare and contrast age- and sex-specific rates of transcervical and pertrochanteric fractures in Quebec, Canada. The data for this study were obtained from a database containing records of all persons discharged from all hospitals in Quebec from 1981 to 1992. Rates of hip fractures were calculated by using the population aged 50 years and older as the denominator, and changes in rates over time were assessed using Poisson regression. There were no statistically significant trends in the changes in rates over time (i.e., 95 percent confidence intervals overlapped the null value). Among women below age 70 years, transcervical fractures were more common, whereas among older women, pertrochanteric fractures predominated. Among men, pertrochanteric fractures predominated at all ages. There was a marked seasonal variation in the occurrence of all hip fractures combined: Compared with the summer months, the relative risk of all hip fractures during the winter was 1.32 (95 percent confidence interval 1.28-1.36). The results of this study indicate that the two subtypes of hip fracture, transcervical and pertrochanteric, have different patterns of occurrence, suggesting different risk factor profiles. Clearly, a multidisciplinary research approach is needed before it will be possible to untangle the complex relation between the metabolic processes occurring at the level of the individual and the distribution of the disease in the population.

Age Distribution↗
PubMed1994

The Ste-Justine Adolescent Idiopathic Scoliosis Cohort Study. Part I: Description of the study.

OBJECTIVES: This study determined the impact of adolescent idiopathic scoliosis (AIS) on health and well being in adulthood by comparing AIS subjects, more than 10 years after referral, to non-AIS subjects according to perceived health status, physical activity, fitness, reproductive health, respiratory condition, and back and neck pain. This paper describes the cohort, the design of the study, and response rates. STUDY DESIGN: The study was designed as a comparative retrospective cohort study. A total of 2,092 patients referred for AIS to Ste-Justine Hospital, Montreal, Quebec, between 1960 and 1979 were identified. A population-based control group was selected in 1989-90 by randomly telephoning persons in Quebec. The control group was approximately frequency-matched to the AIS cohort according to age group and broad geographic region of current residence. METHODS: Patients with adolescent idiopathic scoliosis were traced, and a self-administered questionnaire was sent by post in 1989 to subjects whose addresses were found. Identical questionnaires were sent to subjects in the control group. RESULTS: Seventy-one percent of the cohort (1,476 subjects) returned questionnaires in 1989. Subjects who did not respond to the questionnaires were similar to those who did complete the questionnaires on a number of key factors, except that lower response rates were observed for subjects with scoliotic curves under 20 degrees. The control group consisted of 1,755 subjects (55% response rate). It was similar to the general Quebec population and to the AIS cohort on a number of important sociodemographic factors. CONCLUSION: Comparisons on health outcomes between the two study groups should not be affected by differential patterns of selection or response.

Adolescent↗
PubMed1994

The Ste-Justine Adolescent Idiopathic Scoliosis Cohort Study. Part III: Back pain.

OBJECTIVES: This study determined health and well being of persons with adolescent idiopathic scoliosis (AIS) more than 10 years after referral. This communication will present results related to back pain. STUDY DESIGN: This study was designed as a comparative retrospective cohort study. Subjects referred for AIS between 1960 and 1979 to a large pediatric hospital in Montreal, Quebec, were entered into the cohort. A population-based control group was selected from the general population of Quebec using a telephone survey. METHODS: Back pain was assessed by postal questionnaires administered, in 1990, to the AIS cohort and to the control group. Most outcomes were ordinal and, thus, odds ratios were estimated using ordinal regression while adjusting for potential confounding factors. RESULTS: Among the 1,476 AIS subjects responding, 73% experienced one or more episodes of back pain in the past year, significantly more than the 1,755 controls (56%); for current back pain, these proportions were also significantly different: 44% for AIS subjects and 24% for controls. In comparison to controls, AIS subjects reported pain that was more intense, continuous, generalized throughout the back, and radiating into the extremities. AIS subjects were also more restricted in many usual daily activities. Little variability was observed in the prevalence of current back pain and back pain in the past year according to treatment and degree of curvature. Difficulty with managing pain, lifting, walking, and socializing was, however, associated with severity. The results of this study suggest that back pain is responsible for a considerable amount of disability and handicap in later life. Health professionals involved with the management of persons with AIS need to consider this important outcome and need to put in place procedures for the identification, investigation, prevention, and treatment of back pain.

Activities of Daily Living↗
PubMed1994

The Ste-Justine Adolescent Idiopathic Scoliosis Cohort Study. Part IV: Surgical correction and back pain.

OBJECTIVES: This study determined whether the prevalence, nature, and consequences of back pain in adulthood among persons who underwent Harrington rod instrumentation was related to the number of vertebrae fused, distal level of hook insertion, and degree of correction. STUDY DESIGN: This study was designed as a comparative retrospective cohort study. Subjects referred for AIS between 1960 and 1979 to a large pediatric hospital in Montreal, Quebec, were entered into the cohort. A population based control group was selected from the general population of Quebec using a telephone survey. METHODS: Back pain was assessed by postal questionnaire administered in 1990. Data was analyzed using two multivariate regression models: relative risk regression for dichotomous outcomes and ordinal regression for outcomes measured on an ordinal scale. RESULTS: Among the 723 AIS subjects who had surgery at Ste. Justine's Hospital, 555 completed the questionnaire on back pain. Overall, 73% of patients treated surgically reported back pain in the past year. Proportions varied little by presurgery characteristics or by degree of surgical correction. The distal level of fusion did not influence, in any consistent way, the occurrence of back pain in later life nor the degree of disability associated with back pain. This study does not provide any evidence that extending the level of fusion down even as far as L4 will increase the prevalence of back pain in adulthood.

Adolescent↗
PubMed1994

The Ste-Justine Adolescent Idiopathic Scoliosis Cohort Study. Part II: Perception of health, self and body image, and participation in physical activities.

OBJECTIVES: This study determined the health and well being of persons with adolescent idiopathic scoliosis (AIS) more than 10 years after referral. This communication will present results related to the perception of health, self and body image, and difficulty with selected physical activities. STUDY DESIGN: The study was designed as a comparative retrospective cohort study. Subjects referred for AIS between 1960 and 1979 to a large pediatric hospital in Montreal, Quebec were entered in the cohort. A population-based control group was selected from the general population of Quebec at the time of survey. METHODS: Health outcomes were assessed by a postal questionnaire administered to the AIS cohort and to the control group. Most outcomes were ordinal and, thus, odds ratios were estimated using ordinal regression while adjusting for potential confounding factors. RESULTS: AIS subjects, particularly those who were surgically treated, had a significantly higher prevalence of self-reported arthritis. Scoliosis subjects perceived themselves to be less healthy than other persons the same age and, particularly among women, scoliosis subjects had a poorer perception of body image, and had more physician visits and days ill than control subjects. In addition, male and female AIS subjects had more difficulty with physical activities. This rather negative perception of health could be a result of actual illness or a result of more concern about illness. Nevertheless, they had a more positive perception of self and appeared to be able to cope with their affliction and disfigurement in a positive way.

Adolescent↗
PubMed1994

Projecting the lifetime risk of cancer from exposure to diagnostic ionizing radiation for adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) is a disorder characterized by lateral curvature of the spine and is the most prevalent orthopedic disorder in this age group. The diagnosis and management of AIS requires multiple full-spinal radiographs, leading to potentially high doses of ionizing radiation. The purpose of this study was to estimate in a cohort of subjects with AIS the organ-specific doses of x-ray radiation from spinal radiographs and to calculate the lifetime number of cancers attributable to these exposures. The cohort consisted of AIS patients referred from 1960 to 1979 to a large pediatric hospital in Montreal, Quebec. Organ-specific x-ray doses were estimated using a Monte Carlo procedure that accounted for the radiant energy of the x-ray beam. Cumulative doses for each subject were obtained by summing the estimated doses over all radiographs. These estimates of dose and published estimates of risk from the U.S. National Academy of Sciences Fifth Committee on the Biological Effects of Ionizing Radiation were then incorporated into a life table procedure to project the excess lifetime risk of cancer. About 85% of the 2,181 subjects in the cohort were first referred for scoliosis between the ages of 11 and 17 y. The mean number of radiographs over an average 3-y follow-up period was 12. Organs receiving the highest mean cumulative doses (about 0.03 Gy) were the thyroid gland and the female breast. About 10 excess incident cancer cases (out of a total of 399 projected) and about four excess deaths (out of a total of 247 projected) were estimated to occur over the lifetime of the 1,847 women in the cohort. This is equivalent to an excess lifetime risk of about 1 to 2% (12-25/1,000) among women. Although doses today from spinal radiographs are considerably lower than two decades ago, doses and risks can be further reduced through the use of the posteroanterior view in place of the more traditional anteroposterior view.

Adolescent↗
PubMed1994

Surveillance for stroke in Canada.

The goal of surveillance is to identify patterns of disease occurrence, detect disease outbreaks, develop clues about possible risk factors, find persons that need further investigation, and anticipate health service needs. Two sources of data are available for the purposes of surveillance: primary data, such as those arising from health surveys or local population-based registries; and secondary data, arising from large administrative databases. The effectiveness of any program to monitor the health of a community can be judged by the application of three "r's": right (accuracy), reasonable (cost) and rapid (speed). Programs using primary sources of data satisfy only one of the three "r's," that of accuracy. Programs using secondary sources sacrifice accuracy for speed and cost. The challenge for Canada in setting up surveillance for stroke is that there is a relatively small population unevenly distributed over a very large geographical area. To date, surveillance in Canada has consisted of a combination of individually initiated research projects and government sponsored programs. The main focus has been to tackle the issue of the accuracy of the large databases by validating the discharge codes listed in the provincial hospital discharge databases. Three provinces have carried out independent validation studies yielding remarkably similar results, and this lends confidence that hospital discharge databases will provide a means of carrying out surveillance for at least this one aspect of stroke. It is likely that any program for stroke surveillance in Canada will be multifaceted, involving the use of large computerized databases supplemented by hospital-based registries set up in a few highly motivated local centres. Stroke surveillance will best be accomplished by a joint effort between government and researchers to ensure that the end product is of high quality and will meet the needs of improving the health of Canadians.

Aged↗
PubMed1994

A randomized trial of identification bracelets to prevent falls among patients in a rehabilitation hospital.

This purpose of this study was to determine whether an identification bracelet is effective in preventing falls among high-risk patients who are undergoing in-patient physical rehabilitation. A stratified, randomized, balanced controlled clinical trial was conducted; participants were blinded as to the outcome and the study hypothesis. All patients having one or more risk factors that predisposed them to falls were randomized to receive either a blue identification bracelet or no bracelet. The identification bracelet was intended to increase patients' vigilance about falling. Two risk strata were specified. The high risk stratum consisted of patients with stroke or ataxia, urinary incontinence, or a history of falls. The low risk stratum comprised patients older than 80 years and those on one or more medications that had been identified as contributing to an individual's risk of falling. This report presents the effect of the identification bracelet only among persons in the high-risk stratum. Over 1 year, 65 high-risk subjects were randomized to receive the blue identification bracelet and 69 high-risk subjects were controls. In the intervention group, 27 persons (41%) fell at least once, whereas in the control group 21 persons (30%) fell at least once yielding a hazard ratio of 1.3 (95% confidence interval: 0.8 to 2.4). These results suggest that the identification system was of no benefit in preventing falls among high-risk persons.

Accidental Falls↗
PubMed1993

Risk factors for fractures due to falls.

A matched case-control study was carried out to identify risk factors for fractures due to falls. All falls that occurred at a rehabilitation hospital from 1981 to 1988 were identified and classified as index falls (falls resulting in fractures) or referent falls (falls not resulting in fractures). For each of the 94 index falls, four referent falls were chosen at random (n = 376) from all other falls occurring in the same four week period. The average age of the individuals sustaining the index fall was 76.8 +/- 10.4 years, and 68% were female; in contrast, the average age of the individuals sustaining the referent fall was 72.0 years (+/- 13.2), and 32% were female. Fractures of the hip predominated (n = 40; 42.6%) and fractures of the ribs were the second most prevalent (n = 20; 21.4%). Fractures most often ensured from a fall from the upright position. Of the 24 variables considered in the conditional logistic regression model, advanced age, being female, being ambulatory, experiencing disorientation, use of vitamin supplements, and use of antiulcer medications were significantly associated with the risk of a fracture. Thus, because fractures are potentially life-threatening, strategies to prevent falls should be targeted especially towards those who are at risk to sustain a fracture from a fall. However, to be compatible with rehabilitation goals, the preventive strategies must strike a balance between the achievement of functional autonomy and patient safety.

Accidental Falls↗
PubMed1991

Recovery time of independent function post-stroke.

Stroke patients undergoing physical rehabilitation were monitored daily to determine the length of time needed to recover independent function. Of the 93 patients admitted, there were 45 who could not attain the sitting position independently, 75 who could not walk independently and 75 who could not negotiate the stairs independently. By discharge, 25 of 45 patients (55.6%) were able to attain sitting from supine independently, 35 of 75 patients (46.7%) achieved the ability to walk independently but only 25 of 75 patients (33.3%) learned to negotiate stairs independently. The time from admission to achievement of independent function and the time from onset of stroke to achievement of independent function was modeled in relation to explanatory variables: age, sex, side of lesion, comorbidity, the presence of depression and the extent of impairment in perception, cognition, auditory comprehension and verbal expression. Four variables were found to influence recovery time: age influenced the rate of recovery of walking and stair climbing; perceptual impairment influenced the rate of achieving independent sitting and stair climbing; and depression and comprehension influenced walking.

Activities of Daily Living↗
PubMed1991

Observer variation in assessing neurophysical signs among patients with head injuries.

As an early phase in the development of a valid and reliable measure of the neurophysical sequelae after head injury, we carried out assessments of interrater agreement on representative items. The purpose of this study was to determine the degree of agreement among expert raters who independently measured neurophysical signs on patients undergoing physical rehabilitation after brain injury. Agreement was described using the index of crude agreement, expected agreement and Kappa. Therapists showed a high degree of agreement on those items forming part of a routine neurological assessment: prehension, coordination, voluntary movements and tendon reflexes. Crude agreement ranged from 77.8-100%. There was considerable discordance in assessing muscle tonus, equilibrium and protective reactions, spinal reflexes, tremor and dysmetria (crude agreement ranged from 49.7-97.9%). Although, the number of subjects was small, the information generated from this study will be useful in refining our instrument for the assessment of neurophysical signs.

Adult↗
PubMed1991

The effect of physical therapy for children with motor delay and cerebral palsy. A randomized clinical trial.

Physical therapists recommend neurodevelopmental therapy for cerebral palsy, but its effectiveness has not been fully established. A randomized controlled trial was undertaken to compare the effects over 6 months, of weekly (intensive) and monthly (basic) neurodevelopmental therapy on the motor development of young children with suspected cerebral palsy. Subjects were no older than 18 months when referred for physical therapy because of a motor delay. All those meeting specified criteria were assessed on seven motor development tests: reflex activity, postural reactions, gross motor ability, fine motor skills, mental functioning, dominance of abnormal movement patterns and ability to participate in activities of daily living. The average proportional change in aggregate motor development for the 17 infants on the weekly (intensive) regimen was substantially better than that for the 12 on the monthly (basic) regimen, after adjusting for the child's age, whether the child was born at term or not, and mother's education. A statistical test led to an equivalent of a Student's t = 3.49, which with 24 df was associated with P = 0.0019 (two-sided).

Activities of Daily Living↗
PubMed1991

Changing rates of stroke in the province of Quebec, Canada: 1981-1988.

Using more than 37,000 hospital discharges attributed to hemorrhagic or occlusive stroke in the province of Quebec, Canada, we analyzed trends in stroke incidence during the period 1981-1988. There were large and statistically significant (p less than 0.05) increases in the rates of hemorrhagic stroke over this period. Dramatic increases occurred among men in the rates of both intracerebral (International Classification of Diseases--Ninth Revision [ICD9] code 431) and intracranial (ICD9 code 432) hemorrhagic strokes (40-204% depending on age). In contrast, the rates of occlusion of the precerebral arteries (ICD9 code 433) declined in younger men and women but increased substantially (107%) in older men. Rates of occlusion of the cerebral arteries (ICD9 code 434) declined in men over the age of 50 years and in women aged 50-79 years. Despite the decline in the rate of occlusion of the cerebral arteries, the rate of hemorrhagic stroke appears to have increased. Changes in the hospitalization rates for hemorrhagic stroke were not accompanied by consistent decreases in the case-fatality rate. This finding tends to support the hypothesis of an actual increase in the hospitalization rate fo hemorrhagic stroke rather than an artifactually elevated rate due to enhanced diagnosis by computed tomography.

Adolescent↗
PubMed1990

Change in response time of stroke patients and controls during rehabilitation.

In this study we investigated motor response times of stroke patients at admission to a rehabilitation hospital and again after 6 wk of hospitalization. A prospective comparative study was carried out on 164 stroke patients; 48 hospitalized patients served as controls. Mean motor response times to visual stimuli presented in the left and right visual fields and to centrally presented stimuli were studied. The principle finding was that stroke patients improved significantly in their response times from initial to final evaluation. While at initial assessment they performed significantly more slowly than controls, by final assessment the response times of the two groups did not differ. Visual hemineglect influenced change in response time differentially depending on side of lesion: right hemisphere lesion patients with neglect improved, whereas left hemisphere lesion patients with neglect actually deteriorated. The presence of depression influenced right hemisphere lesion patients' response times and change in response times but it did not have any influence for left hemisphere lesion patients. The findings that response time generally improved during rehabilitation has important implications for the treatment of individuals with brain injury. It will be important to identify therapeutic practices which will be effective in the remediation of response time for all patients. Ultimately the goal of intervening in slow response time is to improve performance of functional activities which are influenced by an individual's ability to respond to visual stimuli.

Aged↗
PubMed1990

Relationship between response time and falls among stroke patients undergoing physical rehabilitation.

This study evaluated the influence of simple motor response time on the risk of falling among 202 stroke patients admitted to a rehabilitation hospital. All patients were tested within 2 weeks of admission to hospital on a computerized response time task. Visual stimuli were presented centrally, in the left and in the right visual fields. Three response times were calculated for each patient. Using the response time from the most impaired field, the 95 fallers generally had slower response times than did the 107 non-fallers (on average, 2.50 s vs. 1.93 s). However, response time was only significantly slower when the visual stimuli were presented in the left visual field (on average, 1.99 s vs. 1.39 s). As response time increased so did the risk of falling, demonstrating a dose-response effect. In comparison to patients with 'normal' response times (0.0-0.50 s), patients with response times between 2.00 s and 2.50 s had a sevenfold increase in the risk of falling. Previous research has shown that the response time of stroke patients improves over time, indicating that response time may be one factor influencing falls which is indeed modifiable. A suggestion is made to include the assessment of response time as a screening tool for identifying persons at elevated risk to fall as it is easily and accurately measured and as interventions aimed at improving response time are available.

Accidental Falls↗