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Biomedical subjects

N E Mayo

Publications and source records attributed to N E Mayo.

At least 19 recordsLinked to original sources
PubMed2004

A task-orientated intervention enhances walking distance and speed in the first year post stroke: a randomized controlled trial.

OBJECTIVE: To evaluate the efficacy of a task-orientated intervention in enhancing competence in walking in people with stroke. DESIGN: Two-centre observer-blinded stratified block-randomized controlled trial. SETTING: General community. SUBJECTS: Between May 2000 and February 2003, 91 individuals with a residual walking deficit within one year of a first or recurrent stroke consented to participate. INTERVENTIONS: The experimental intervention comprised 10 functional tasks designed to strengthen the lower extremities and enhance walking balance, speed and distance. The control intervention involved the practice of upper extremity activities. Subjects in both groups attended sessions three times a week for six weeks. MAIN MEASURES: Six-minute walk test (SMWT), 5-m walk (comfortable and maximum pace), Berg Balance Scale, timed 'up and go'. RESULTS: At baseline, subjects in the experimental (n = 44) and control (n = 47) groups walked an average distance of 209 m (SD = 126) and 204 m (SD =131), respectively, on the SMWT. Mean improvements of 40 m (SD =72), and 5 m (SD =66) were observed following the experimental and control interventions, respectively. The between-group difference was 35 m (95% confidence interval (CI) 7, 64). Significant between-group effects of 0.21 m/s (95% CI 0.12, 0.30) and of 0.11 m/s (95% CI 0.03, 0.19) in maximum and comfortable walking speed, respectively, were observed. People with a mild, moderate or severe walking deficit at baseline improved an average of 36 (SD =96), 55 (SD = 56) and 18 m (SD = 23), respectively, in SMWT performance following the experimental intervention. CONCLUSIONS: Study findings support the efficacy of a task-orientated intervention in enhancing walking distance and speed in the first year post stroke, particularly in people with moderate walking deficits.

Adult↗
PubMed2001

Waiting time for breast cancer surgery in Quebec.

BACKGROUND: Currently there is no agreement on the optimal time to treatment of breast cancer; however, given the considerable emphasis on early detection, one would expect a similar emphasis on early treatment. The purpose of our study was to assess the time interval to surgery from initiation of diagnosis among Quebec women with breast cancer and to examine the influence on waiting time of age, pattern of care and cancer stage. METHODS: Records of physician fee-for-service claims and of hospital admissions were obtained for all Quebec women who underwent an invasive procedure for the diagnosis or treatment of breast cancer between 1992 and 1998. Waiting time was calculated as the number of days between the first diagnostic procedure and surgical treatment. RESULTS: There were 29,606 episodes of breast cancer surgery among 28,100 women: 5922 mastectomies and 23,684 lumpectomies. The absolute number of episodes of breast cancer treated with surgery rose from 3626 in 1992 to 5162 in 1998. The overall median waiting time was 34 days (interquartile range [IQR] 19-62); 13.5% of the women waited longer than 90 days. The median waiting time rose from 29 days (IQR 15-54) in 1992 to 42 days (IQR 24-72) in 1998, representing a relative increase of 37% (95% confidence interval [CI] 32%-43%) after adjusting for age and cancer stage. The median waiting time increased with the number of diagnostic procedures, from 24 days (IQR 14-42) with 1 procedure to 48 days (IQR 27-84) with 3 procedures to 72 days (IQR 43-121) with 4 procedures, representing adjusted relative increases of 97% (95% CI 91%-103%) and 194% (95% CI 181%-208%), respectively. The proportion of women receiving 3 or more diagnostic procedures before surgery increased steadily over the study period, from 19.2% in 1992 to 33.0% in 1998. The median waiting time was shorter with more advanced stages of cancer: 53 days (IQR 30-86) for carcinoma in situ, 35 (IQR 20-62) for localized disease, 28 (IQR 16-49) for regional disease and 24 (IQR 11-52) for disseminated disease. INTERPRETATION: Waiting time between initial diagnosis and first surgery for breast cancer has increased substantially in Quebec between 1992 and 1998. Possible explanations include increased demand, decreased resources and changes in patterns of care.

Adult↗
PubMed2001

Responsiveness and predictability of gait speed and other disability measures in acute stroke.

OBJECTIVES: To identify the most responsive method of measuring gait speed, to estimate the responsiveness of other outcome measures, and to determine whether gait speed predicts discharge destination in acute stroke. DESIGN: A prospective cohort study. SETTING: Five acute-care hospitals. PATIENTS: Fifty subjects with residual gait deficits after a first-time stroke. INTERVENTIONS: Five- (5mWT) and 10-meter walk tests (10mWT) at comfortable and maximum speeds, with 2 evaluations conducted an average +/- standard deviation (SD) of 8 +/- 3 and 38 +/- 5 days poststroke. MAIN OUTCOME MEASURE: Standardized response mean (SRM = mean change/SD of change) was used to estimate responsiveness for each walk test, the Berg Balance Scale, the Barthel Index, the Stroke Rehabilitation Assessment of Movement (STREAM), and the Timed Up and Go (TUG). RESULTS: The SRMs were 1.22 and 1.00 for the 5mWT, and.92 and.83 for the 10mWT performed at a comfortable and maximum pace, respectively. The SRMs for the Berg Balance Scale, the Barthel Index, the STREAM, and the TUG were 1.04,.99,.89, and.73, respectively. The probability of discharge to a rehabilitation center for persons walking at < or = 0.3m/s or > 0.6m/s at the first evaluation was.95 and.22, respectively. CONCLUSIONS: The 5mWT at a comfortable pace is recommended as the measure of choice for clinicians and researchers who need to detect longitudinal change in walking disability in the first 5 weeks poststroke.

Activities of Daily Living↗
PubMed2001

The relationship between health related quality of life and disease activity and damage in systemic lupus erythematosus.

OBJECTIVE: To evaluate the relationship between self-reported quality of life and disease activity, damage, impairment, disability, and handicap in systemic lupus erythematosus (SLE). METHODS: In this cross sectional study disease activity was measured with the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and the Systemic Lupus Activity Measure (SLAM), and damage by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) damage index (SDI). Quality of life was assessed by the Medical Outcome Survey Short Form 36 (SF-36) and the EuroQol (EQ-5D). Multiple linear regression was used to identify significant associations of patients' health status, and logistic regression was used to evaluate the relationship of each of the 5 dimensions of the EQ-5D in terms of impairment, disability, and handicap. RESULTS: Damage was associated with the Physical Function (PF) and Social Function subscales of the SF-36. Disease activity was associated with the General Health (GH) subscale. Ability to carry out usual activities was strongly related to PF and GH as well as to global rating of the thermometer rating scale of the EQ-5D. Role Physical (RP) and Bodily Pain (BP) of the SF-36 were also associated with the EQ-5D rating scale. In addition, patients' ratings of anxiety and depression were strongly related to the Mental Health (MH) summary scale of the SF-36. CONCLUSION: Perceived health status of patients with lupus was associated with disease activity, damage, role physical, bodily pain, capacity for usual activity, and mobility. EQ-5D is a valid instrument for the measure of health related quality of life in SLE.

Adult↗
PubMed2000

A review of the association between cigarette smoking and the development of nonspecific back pain and related outcomes.

STUDY DESIGN: A structured review of the epidemiologic literature was performed. Thirty-eight studies published in peer-reviewed journals were reviewed. The methodologic strengths and weaknesses of the studies were described and assessed qualitatively. Four studies were excluded because of difficulties in design or interpretation. OBJECTIVES: To provide a systematic analysis of the literature to assess the evidence as to whether smoking is associated with the prevalence and incidence of nonspecific back pain and related outcomes. SUMMARY OF BACKGROUND DATA: Evidence has been gathering regarding the association of smoking with nonspecific back pain and other back disorders, but a comprehensive summary and evaluation of the data have not been published. RESULTS: Positive associations between current smoking and nonspecific back pain were found in 18 of 26 studies in men and 18 of 20 studies in women. For sciatica and herniated discs, there were four of eight and one of five positive studies in men and women, respectively. The majority of these studies were cross-sectional (18 in men and 16 in women), with only a handful of prospective studies. Positive associations between past smoking and nonspecific back pain were reported in five of nine studies in men and five of six studies in women. In addition, increases in the prevalence and/or incidence of nonspecific back pain were found in the majority of studies in which level of consumption was analyzed and reported. An attempt was made to assess whether these results could be artifactual arising from selection bias, confounding bias, publication bias, or errors in measurement. As well, the biologic mechanisms were summarized that have been suggested by various investigators. CONCLUSIONS: The available data are consistent with the notion that smoking is associated with the incidenceand prevalence of nonspecific back pain, but there are too few studies to make any conclusions for the other end points (e.g., sciatica, herniated discs). It cannot be ruled out that the association is a statistical artifact arising from either selection or confounding factors, because the evidence for nonspecific low back pain derives mostly from cross-sectional studies. In addition, it cannot be stated unequivocally that smoking preceded back pain. Long-term follow-up studies are needed to eliminate the possibility that chronic back pain preceded smoking, to better estimate dose-response correlations, and to perform biologic measurements to elucidate possible mechanisms.

Adolescent↗
PubMed2000

There's no place like home : an evaluation of early supported discharge for stroke.

BACKGROUND AND PURPOSE: Because stroke management is aimed at facilitating community reintegration, it would be logical that the sooner the patient can be discharged home, the sooner reintegration can commence. The purpose of this study was to determine the effectiveness of prompt discharge combined with home rehabilitation on function, community reintegration, and health-related quality of life during the first 3 months after stroke. METHODS: A randomized trial was carried out involving patients who required rehabilitation services and who had a caregiver at home. When medically ready for discharge, persons with stroke were randomized to either the home intervention group (n=58) or the usual care group (n=56). The home group received a 4-week, tailor-made home program of rehabilitation and nursing services; persons randomized to the usual care group received services provided through a variety of mechanisms, depending on institutional, care provider, and personal preference. The main outcome measure was the Physical Health component of the Measuring Outcomes Study Short-Form-36 (SF-36). Associated outcomes measures included the Timed Up & Go (TUG), Barthel Index (BI), the Older Americans Resource Scale for instrumental activities of daily living (OARS-IADL), Reintegration to Normal Living (RNL), and the SF-36 Mental Health component. RESULTS: The total length of stay for the home group was, on average, 10 days, 6 days shorter than that for the usual care group. There were no differences between the 2 groups on the BI or on the TUG at either 1 or 3 months after stroke; however, there was a significantly beneficial impact of the home intervention on IADL and reintegration (RNL). By 3 months after stroke, the home intervention group showed a significantly higher score on the SF-36 Physical Health component than the usual care group. The total number of services received by the home group was actually lower than that received by the usual care group. CONCLUSIONS: Prompt discharge combined with home rehabilitation appeared to translate motor and functional gains that occur through natural recovery and rehabilitation into a greater degree of higher-level function and satisfaction with community reintegration, and these in turn were translated into a better physical health.

Aged↗
PubMed1999

The association between cigarette smoking and back pain in adults.

STUDY DESIGN: A retrospective cohort study of adolescent idiopathic scoliosis. A comparison group of persons without scoliosis was also selected randomly from the general population. OBJECTIVES: To estimate the association between level of cigarette smoking and the prevalence and severity of back pain. METHODS: A postal questionnaire was used to elicit information on smoking histories, a variety of indices of low back pain, and potential confounding factors. The association between smoking and back pain was estimated separately for men and women in the cohort and in the comparison group using ordinal regression models. RESULTS: The questionnaire was completed by 1287 women and 184 men who had adolescent idiopathic scoliosis and by 1130 women and 621 men in the comparison population who did not have scoliosis. Statistically significant associations between back pain and current cigarette smoking were found in the two groups of women and men with scoliosis, but not among men selected from the general population. In the three former groups, proportional odds ratios comparing current smokers to persons who never smoked ranged from 1.4 to 1.9. Among current smokers, the prevalence of back pain increased with cigarette consumption, and the proportional odds ratios ranged from 1.2 to 1.8 per 10 pack-years (no. of cigarettes smoked per day x no. of years/20). In these three groups, intensity, frequency, and duration of episodes of back pain also were found to increase with smoking consumption. CONCLUSION: The finding that smokers have more frequent episodes of back pain may imply that smoking exacerbates back pain, and the observation that stronger associations between back pain and smoking were found in the scoliosis cohort suggests that smoking may have a greater impact on persons with damaged spines.

Adolescent↗
PubMed1999

Sample size calculations in studies using the EuroQol 5D.

Health-related quality of life (HRQoL) instruments are increasingly used as outcome variables in clinical trials, leading to a requirement for sample size calculations based on these variables. This paper aims to provide a guide to sample size calculations for use with the EuroQol-5D. The paper focuses on sample sizes required for comparative studies, and uses scores from two reference groups of general population and critically ill patients to determine sample sizes using the three parts of the EQ-5D (descriptive system, visual analogue scale (VAS), and EQ-5D index). The effect on sample sizes of different methods of categorising the three variables are compared, and comparisons are also made between sample sizes using parametric and non-parametric methods. Sample sizes required when the EQ-5D descriptive system is used as a binary variable (problems/no problems) are higher than or equal to those required when each dimension is categorised in three levels of severity (no problems, moderate problems, extreme problems). The use of three categories is appropriate in ill populations, though in more healthy populations two categories should be used. Due to the slight skewness of VAS data, and the equality of results using parametric and non-parametric methods, sample size calculations using the VAS should be based on a parametric approach. Sample sizes were considerably higher for the EQ-5D index when predefined intervals, as opposed to a score frequency based categorisation, were used with the general population reference group. Using the EQ-5D index in ill populations, it is recommended that sample size calculations are based on parametric methods, whilst in healthier populations non-parametric methods should be used.

Critical Illness↗
PubMed1998

A new approach to retrain gait in stroke patients through body weight support and treadmill stimulation.

BACKGROUND AND PURPOSE: A new gait training strategy for patients with stroke proposes to support a percentage of the patient's body weight while retraining gait on a treadmill. This research project intended to compare the effects of gait training with body weight support (BWS) and with no body weight support (no-BWS) on clinical outcome measures for patients with stroke. METHODS: One hundred subjects with stroke were randomized to receive one of two treatments while walking on a treadmill: 50 subjects were trained to walk with up to 40% of their body weight supported by a BWS system with overhead harness (BWS group), and the other 50 subjects were trained to walk bearing full weight on their lower extremities (no-BWS group). Treatment outcomes were assessed on the basis of functional balance, motor recovery, overground walking speed, and overground walking endurance. RESULTS: After a 6-week training period, the BWS group scored significantly higher than the no-BWS group for functional balance (P = 0.001), motor recovery (P = 0.001), overground walking speed (P = 0.029), and overground w alking endurance (P = 0.018). The follow-up evaluation, 3 months after training, revealed that the BWS group continues to have significantly higher scores for overground walking speed (P = 0.006) and motor recovery (P = 0.039). CONCLUSIONS: Retraining gait in patients with stroke while a percentage of their body weight was supported resulted in better walking abilities than gait training while the patients were bearing their full weight. This novel gait training strategy provides a dynamic and integrative approach for the treatment of gait dysfunction after stroke.

Adult↗
PubMed1998

Inclement weather and the risk of hip fracture.

An association between inclement weather and hip fractures has been documented, but specific subgroups of the population at particular risk have not been identified. We obtained information that included hospitalization data on all hip fractures in Montreal from 1982 to 1992, and meteorologic data on the amount of snow, rain, and freezing rain and the temperature on each day of study. We used a cross-level design to examine the association between the rate of hip fractures and the meteorologic conditions on the day of the accident in both sexes and five age strata. There were a total of 18,455 hip fractures over the 4,018-day study period. We found a cyclical pattern in occurrence of hip fractures, with the peak occurring in mid-December among women and the first week of January among men. The pattern was less pronounced among women than men, with peak-to-trough ratios of 1.2 and 1.4, respectively. Days with lower temperatures, snow, and freezing rain were associated with increased rates of hip fracture. The meteorologic condition carrying the greatest risk was freezing rain. The association between inclement weather and hip fractures was stronger among younger persons, both women and men. After adjusting for meteorologic variables, there remained increases in winter of 5% among women and 12% among men. The residual effect of winter may be related to cold temperatures or due to an accumulation of ice and snow even on fine days. Other possible mechanisms to explain the residual effect of winter include slower reaction times and winter bone loss, both of which could affect indoor as well as outdoor falls.

Age Factors↗
PubMed1998

Adverse reproductive outcomes among women exposed to low levels of ionizing radiation from diagnostic radiography for adolescent idiopathic scoliosis.

In a cohort of women followed up for adolescent idiopathic scoliosis, we assessed the association between exposure to ionizing radiation from diagnostic radiography received in adolescence and subsequent adverse reproductive outcomes in adulthood. We estimated risk for unsuccessful attempts at pregnancy, spontaneous abortions, low birthweight (<2,500 gm), congenital malformations, and stillbirths according to dose to the ovaries. We used regression models for binary and continuous outcomes, accounting for key covariates and for clustering in the data that arose from women having multiple pregnancies. Risks in the adolescent idiopathic scoliosis cohort were higher than in the reference group for unsuccessful attempts at pregnancy [adjusted odds ratio (OR) = 1.33; 95% confidence interval (CI) = 0.84-2.13], spontaneous abortions (OR = 1.35; 95% CI = 1.06-1.73), and congenital malformations (OR = 1.20; 95% CI = 0.78-1.84), but the odds ratios did not increase monotonically by dose to the ovaries. There were fewer stillbirths (OR = 0.38; 95% CI = 0.15-0.97) and low-birthweight infants in the adolescent idiopathic scoliosis cohort (OR = 0.84; 95% CI = 0.59-1.21). Nevertheless, when the analysis of low birthweight was restricted to the adolescent idiopathic scoliosis cohort, the adjusted odds ratios were found to increase by quartiles of dose (median dose of 0.69 cGy): 1; 1.43 (95% CI = 0.54-3.90); 2.24 (95% CI = 0.89-5.94); and 2.34 (95% CI = 1.02-5.62). We also found that the adjusted mean birthweight decreased with increasing dose by 37.6 gm per cGy (standard error = 23.5 gm per cGy). Associations between adverse reproductive outcomes and radiotherapy have been observed previously, but this is the first study in which an association with birthweight has been found with diagnostic radiography.

Abortion, Spontaneous↗
PubMed1997

Statistical assessment of ordinal outcomes in comparative studies.

Ordinal regression is a relatively new statistical method developed for analyzing ranked outcomes. In the past, ranked scales have often been analyzed without making full use of the ordinality of the data or, alternatively, by assigning arbitrary numerical scores to the ranks. While ordinal regression models are now available to make full use of ranked data, they are not used widely. This article, directed to clinical researchers and epidemiologists, provides a description of the properties of these methods. Using ordinal measures of back pain in a follow-up study of adolescent idiopathic scoliosis, we illustrate the advantages of those methods and describe how to interpret the estimated parameters. Comparisons with binary logistic regression are made to show why a single dichotomization of the ordinal scale may lead to incorrect inferences. Two ordinal models (the proportional odds and the continuation ratio models) are discussed, and the goodness-of-fit of these models is examined. We conclude that ordinal regression is a tool that is powerful, simple to use, and produces an interpretable parameter that summarizes the effect between groups over all levels of the outcome.

Epidemiologic Methods↗
PubMed1997

Nonmedical bed-days for stroke patients admitted to acute-care hospitals in Montreal, Canada.

BACKGROUND AND PURPOSE: Reducing the amount of nonoptimal time stroke patients spend in the hospital should be a priority because prolonged hospitalization is not only costly but may be detrimental for persons with stroke through deconditioning, social isolation, and the fostering of dependent relationships. The purpose of this study was to determine the amount of time spent by stroke patients in acute-care hospitals that was not justified for medical reasons and to identify mechanisms contributing to nonmedical bed-days. METHODS: A retrospective cohort study was performed with 2232 persons admitted for acute stroke to one of 13 hospitals in Montreal, Canada, during 1991. Information was collected on the patient, the stroke, functional status, course in hospital, services, and discharge. Nonmedical bed-days were calculated as the difference between the time to meet specified criteria and time of discharge. Associations with nonmedical bed-days were estimated with adjustment for patient mix. RESULTS: Acute-care stay averaged 27 days, yielding 60,279 bed-days. Almost 50% of the cohort remained in the hospital after meeting criteria for medical discharge, resulting in 43% of total bed-days not accounted for medically. Fifty percent of persons with delayed discharge did not go home but were discharged to another acute-care hospital or to rehabilitation or long-term care, accounting for 66% of the nonmedical bed-days. Hospital and discharge destination remained strongly associated with nonmedical days, even after adjustment for patient mix. CONCLUSIONS: The single greatest contributor to excessive nonmedical stay appeared to be the need in Quebec for increased access to alternate levels of care, including skilled nursing facilities and rehabilitation centers.

Adult↗
PubMed1997

Hospitalization and case-fatality rates for subarachnoid hemorrhage in Canada from 1982 through 1991. The Canadian Collaborative Study Group of Stroke Hospitalizations.

BACKGROUND AND PURPOSE: Subarachnoid hemorrhage (SAH) has a different epidemiological profile from other types of stroke and a different etiology. Although there has been a general decline in overall stroke incidence since the 1950s, secular trends for SAH have been modest. In contrast to other stroke types, changes in incidence over the last few decades have been less clear. The purpose of this study was to estimate hospitalization and case-fatality rates of SAH according to age, sex, calendar year, and season. METHODS: Data were obtained for each of Canada's 10 provinces for the 10 fiscal years 1982 through 1991. All hospitalizations of persons 15 years of age or older with a primary diagnosis at discharge coded 430 according to the International Classification of Diseases, 9th Revision, were included. Rates of SAH per 100,000 population were calculated for men and women for 5-year age groups, by calendar year, and by season. Annual age- and sex-specific (hospital) case-fatality rates up to 30 days were also calculated. Additionally, hospital deaths from this study were related to national SAH mortality statistics. RESULTS: A total of 14145 women and 8995 men were discharged with a primary diagnosis of SAH during the 10-year period. In contrast to other types of stroke, the rates of SAH were higher for women than for men at all ages. The age-standardized rates of SAH in 1991-1992 were 11.2 per 100000 women and 8.0 per 100000 men. For women, there was a 6% (95% confidence interval [CI], -12% to 0%) decline in hospitalization rates over that period; for men, the decline was 15% (95% CI, -21% to -8%). The peak season for SAH among women was winter; for men the peaks were in the fall and spring. For both sexes, the lowest occurrence was in the summer. Over this period, 30-day case-fatality rates declined somewhat (statistically significant only in the age group of 35 to 44 years). The number of deaths enumerated from hospital discharges was 20% to 50% lower than the number recorded on national mortality statistics, indicating that a proportion of SAH deaths occurred before (or after) the hospital stay. CONCLUSIONS: Although rates of hospitalization for SAH declined over this period, SAH remains an important neurological event affecting individuals at relatively young ages. The rates were higher for women than for men at all ages. Total (in-hospital) case-fatality rate remains high.

Adolescent↗
PubMed1996

Reducing the lifetime risk of cancer from spinal radiographs among people with adolescent idiopathic scoliosis.

STUDY DESIGN: Data from a retrospective cohort study of people with adolescent idiopathic scoliosis were combined with information on full-spinal radiographs to estimate contemporary x-ray doses and lifetime risks for development of cancer. OBJECTIVES: To project the lifetime risk for development of cancer from diagnostic radiographs for people with adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: Although a twofold excess risk for breast cancer has been reported for women treated for scoliosis between 1925 and 1965, information on the cancer risks associated with scoliosis management today is sparse. Specifically, there is a lack of up-to-date information on the number of spinal radiographs taken, the organ-specific x-ray doses from current radiographic techniques, and the projected cancer risks. METHODS: The cohort consisted of subjects with adolescent idiopathic scoliosis who were referred to the scoliosis clinic of a large pediatric hospital between 1965 and 1979 in Montreal, Quebec, Canada. Based on radiographic equipment and practices implemented in 1982, organ-specific x-ray doses to the thyroid gland, female breast, respiratory organs, digestive organs, and bone marrow were calculated using Monte Carlo methods. These doses were incorporated into a life table procedure to calculate theoretic lifetime cancer risks. For all organs except the thyroid gland, dose-response models from the United States National Academy of Sciences Fifth Committee on the Biological Effects of ionizing Radiation were used. For thyroid cancer, a risk model was derived from a study of thyroid cancer incidence after x-ray treatment for tinea capitis. RESULTS: The average number of spinal radiographs was 12 for women (80% anteroposterior or posteroanterior) and 10 for men (78% anteroposterior or posteroanterior). Cumulative x-ray doses were in general higher in adolescents who were referred as younger teenagers than at later ages, and doses increased with the size of the spinal curve. Depending on the age at referral and curve size, the total excess lifetime cancer risks were calculated to range from 42 to 238 cases per 100,000 women and 14 to 79 cases per 100,000 men. For subjects who underwent surgery (those exposed to the highest doses), the lifetime number of cancer cases over and above background was almost as great as the number of thyroid cancers that would occur in the absence of radiation exposure. If the anteroposterior view was replaced by the posteroanterior view, a three- to sevenfold reduction in cumulative doses to the thyroid gland and the female breast would be achieved, yielding three- to fourfold reductions in the lifetime risk of breast cancer and a halving of the lifetime risk of thyroid cancer. CONCLUSIONS: The cancer risks from full-spinal radiographs for scoliosis are not negligible and can be reduced from one half to three quarters if the anteroposterior view is replaced with the posteroanterior view.

Adolescent↗
PubMed1996

What are the costs of queuing for hip fracture surgery in Canada?

This paper investigates the effect of wait time for hip fracture surgery in Canada on post-surgery length of stay in hospital and inpatient mortality. After controlling for observed and unobserved patient and hospital characteristics, pre-surgery delay has little effect on either of the two outcome variables. Patients from higher income postal-codes experience only slightly shorter delays, and income has no substantial effect on post-surgery outcomes. For hip fracture patients surgery delay may lead to greater pre-surgery inpatient costs and more patient discomfort, but we find no evidence of a detrimental impact on post-surgery outcomes.

Aged↗
PubMed1996

Hospitalization and case-fatality rates for stroke in Canada from 1982 through 1991. The Canadian Collaborative Study Group of Stroke Hospitalizations.

BACKGROUND AND PURPOSE: The purpose of this study was to estimate rates of hospitalization and in-hospital case-fatality for cerebral infarction and intracerebral hemorrhage in Canada and to describe variation in rates by age, sex, and calendar period. METHODS: Data were obtained from hospitalization databases for each of Canada's 10 provinces for the 10 fiscal years of 1982 through 1991. All hospitalizations of persons 15 years of age or older with a primary diagnosis at discharge coded 431, 434, or 436 according to the International Classification of Disease, 9th Revision, were included. Rates per 100,000 population were calculated for intracerebral hemorrhage and cerebral infarction, for men and women, and for five age groups. Annual age- and sex-specific, 30-day, in-hospital case-fatality rates were also calculated. RESULTS: A total of 335,283 discharges for stroke were enumerated over the 10-year period (309,631 cerebral infarctions and 25 652 intracerebral hemorrhages). A significant decline of approximately 1% per year was observed for the rate of cerebral infarctions. For hemorrhages, the reverse was seen. For men there was a 44% increase over the 10-year period, and for women there was a 34% increase. In-hospital case-fatality rates for cerebral infarctions increased with age but did not differ by sex when age was considered. For the five age groups of 15 to 54, 55 to 64, 65 to 74, 75 to 84 and > or = 85 years, rates were 6%, 8%, 12%, 18% and 27%, respectively. For intracerebral hemorrhage, the in-hospital case-fatality rates declined significantly over time from approximately 36% to 29%, 55% to 37%, 49% to 41%, 66% to 45%, and 72% to 59% for the five age groups, respectively. CONCLUSIONS: The possibility that these changes are artifactual could not be ruled out, but because there is no obvious risk in assuming that they are not, it would be prudent to investigate their causes further.

Adolescent↗