Colin L. Soskolne

Articular mobility in an African population.

There is considerable variation in the range ofmovements which are possible in the joints of normal individuals. In general, females are more mobile than males, while joint laxity decreases with age (Ellis and Bundick, 1956; Wynne-Davies, 1971). Ethnic differences in joint mobility have also been described. For instance, Negroes and Indians have been shown to have a greater range of movements than Caucasians of the same age and sex (Harris and Joseph, 1949). Similarly, in an investigation in Cape Town, Indians were found to be more loose-jointed than indigenous Xhosa and Hlubi, who in turn had a greater degree of joint laxity than white South Africans (Schweitzer, 1970). Articular mobility is a graded trait and at one end of the spectrum a considerable degree of joint laxity may occur in normal individuals (Wood, 1971). Apart from this form of hypermobility, joint laxity is also a component of a variety of genetically determined syndromes (McKusick, 1966; Beighton, 1970). It can also occur in the absence of other stigmata as a simple inherited entity (Sturkie, 1941; Carter and Sweetnam, 1958, 1960; Beighton and Horan, 1970). It has been suggested that hypermobile individuals are prone to orthopaedic disorders, such as degenerative joint disease, dislocations, joint effusions, and muscular pains (Hass and Hass, 1958; Kirk, Ansell, and Bywaters, 1967; Grahame, 1971). Articular laxity has also been implicated as an important factor in the genesis of congenital dislocation of the hip (Wynne-Davies, 1970). For these reasons, hypermobility may well be of considerable clinical significance. An epidemiological survey has recently been completed among the Tswana people of the Western Transvaal. The main aims of this investigation were the study of various bone and joint conditions, but the survey also provided an excellent opportunity for the measurement of the range ofjoint movements in a large number of individuals and for the assessment of the influence of age, sex, and somatotype on their articular mobility. The importance of joint laxity in the production of non-specific musculo-skeletal complaints was also evaluated. The purpose of this paper is to present the results of this investigation and to discuss the clinical significance of the observations which were made.

Surgeon-related factors and outcome in rectal cancer.

OBJECTIVE To determine whether surgical subspecialty training in colorectal surgery or frequency of rectal cancer resection by the surgeon are independent prognostic factors for local recurrence (LR) and survival. SUMMARY BACKGROUND DATA Variation in patient outcome in rectal cancer has been shown among centers and among individual surgeons. However, the prognostic importance of surgeon-related factors is largely unknown. METHODS All patients undergoing potentially curative low anterior resection or abdominoperineal resection for primary adenocarcinoma of the rectum between 1983 and 1990 at the five Edmonton general hospitals were reviewed in a historic-prospective study design. Preoperative, intraoperative, pathologic, adjuvant therapy, and outcome variables were obtained. Outcomes of interest included LR and disease-specific survival (DSS). To determine survival rates and to control both confounding and interaction, multivariate analysis was performed using Cox proportional hazards regression. RESULTS The study included 683 patients involving 52 surgeons, with > 5-year follow-up obtained on 663 (97%) patients. There were five colorectal-trained surgeons who performed 109 (16%) of the operations. Independent of surgeon training, 323 operations (47%) were done by surgeons performing < 21 rectal cancer resections over the study period. Multivariate analysis showed that the risk of LR was increased in patients of both noncolorectal trained surgeons (hazard ratio (HR) = 2.5, p = 0.001) and those of surgeons performing < 21 resections (HR = 1.8, p < 0.001). Stage (p < 0.001), use of adjuvant therapy (p = 0.002), rectal perforation or tumor spill (p < 0.001), and vascular/neural invasion (p = 0.002) also were significant prognostic factors for LR. Similarly, decreased disease-specific survival was found to be independently associated with noncolorectal-trained surgeons (HR = 1.5, p = 0.03) and surgeons performing < 21 resections (HR = 1.4, p = 0.005). Stage (p < 0.001), grade (p = 0.02), age (p = 0.02), rectal perforation or tumor spill (p < 0.001), and vascular or neural invasion (p < 0.001) were other significant prognostic factors for DSS. CONCLUSION Outcome is improved with both colorectal surgical subspecialty training and a higher frequency of rectal cancer surgery. Therefore, the surgical treatment of rectal cancer patients should rely exclusively on surgeons with such training or surgeons with more experience.

Physicians' Reasons for Not Entering Eligible Patients in a Randomized Clinical Trial of Surgery for Breast Cancer

We studied the reasons surgical principal investigators chose not to enter patients in a large, multicenter trial sponsored by a cooperative group. In 1976 the National Surgical Adjuvant Project for Breast and Bowel Cancers (NSABP) initiated a clinical trial to compare segmental mastectomy and postoperative radiation, or segmental mastectomy alone, with total mastectomy. Because the low rates of accrual were threatening to close the trial prematurely, we mailed a questionnaire to the 94 NSABP principal investigators, asking why they were not entering eligible patients in the trial. A response rate of 97 per cent was achieved. Physicians who did not enter all eligible patients offered the following explanations: (1) concern that the doctor-patient relationship would be affected by a randomized clinical trial (73 per cent), (2) difficulty with informed consent (38 per cent), (3) dislike of open discussions involving uncertainty (22 per cent), (4) perceived conflict between the roles of scientist and clinician (18 per cent), (5) practical difficulties in following procedures (9 per cent), and (6) feelings of personal responsibility if the treatments were found to be unequal (8 per cent). Further investigation into the behavioral aspects of the investigator-patient relationship is particularly pressing, since fear of change in this relationship was the most common reason given for not entering eligible patients in the trial.

Mortality and Institutionalization Following Hip Fracture

OBJECTIVES: To identify determinants of mortality and institutionalization after hip fracture and to identify those older hip fracture patients at high risk of death or institutionalization after hip fracture.

Functional dependence after hip fracture.

Cree M, Carriere KC, Soskolne CL, Suarez-Almazor M: Functional dependence after hip fracture. Am J Phys Med Rehabil 2001;80:736–743. Objectives: To identify patients at high risk of functional dependence and examine the progression of disability after a hip fracture. Design: This was a population-based prospective inception cohort study of all patients aged 65+ yr who fractured a hip between July 1996 and August 1997. Demographic, socioeconomic, social support, and health status information was assessed in the hospital and 3 mo postfracture. Results: The analysis included 367 patients. Almost all patients with cognitive impairment were functionally dependent postfracture, with new disabilities frequently occurring in transferring. Among patients of high mental status, increased risk of functional dependence was associated with advanced age, more co-morbidities, hip pain, poor self-rated health, and previous employment in a prestigeous occupation. Bathing disability was most likely in those who functioned independently prefracture; a disability in dressing was most common otherwise. Conclusion: Hip pain is amenable to treatment and may improve chances of functional recovery. Patients can be assisted in regaining prefracture function if they are targeted for rehabilitation on the basis of mental status. The focus should be on bathing and dressing among patients of high cognition and transferring among those patients with mental impairment.

Physician response to informed consent regulations for randomized clinical trials.

To improve our understanding of physician reluctance to participate in randomized clinical trials, we examined physician responses to the regulation of obtaining written informed consent. Between June 1984 and February 1985 a purposive sample of 170 breast cancer specialists from eight countries completed a self‐administered questionnaire and follow‐up interview. The sample included 90 medical oncologists, 65 surgeons, and 29 radiotherapists. Responses to individual questions are presented in three global categories: (1) physician role—physicians believed that their view of their professional “self” was not compatible with informed consent regulations; (2) physician autonomy—physicians perceived a loss of individual decision‐making power and an increase in professional accountability; and (3) physician‐patient relationship—physicians stated that informed consent regulations influenced what they told trial patients and affected the ensuing doctor‐patient relationship. Respondents developed complex methods to accommodate the incongruities they perceived between their view of their professional self and the need to obtain informed consent.

Calibration of the dietary questionnaire for the Canadian study of diet, lifestyle and health cohort

OBJECTIVE For proper interpretation of results from epidemiological studies that use food-frequency questionnaires (FFQs), it is necessary to know the relationship between reported intakes from the FFQ and true usual intake. In this paper, we report a calibration study conducted to investigate the performance of the FFQ used in a cohort study, the Canadian Study of Diet, Lifestyle and Health. METHODS Over a 1-year period, 151 men and 159 women completed a full set of questionnaires including a self-administered baseline FFQ, three 24-hour diet recalls administered by telephone, and a second FFQ self-administered subsequently. The association between the nutrient estimates derived from the FFQs and the diet recalls was evaluated by calculating deattenuated Pearsons correlation coefficients. RESULTS FFQs estimated mean daily nutrient intakes higher than the diet recalls. When the log-transformed and energy-adjusted nutrient intakes from the average of three 24-hour recalls were compared against the baseline FFQ, the following deattenuated correlations were obtained in men and women, respectively: total energy 0.44 and 0.32, total fat 0.64 and 0.68, saturated fat 0.68 and 0.70, dietary fibre 0.65 and 0.44, vitamin E 0.32 and 0.37, vitamin C 0.40 and 0.37, beta-carotene 0.34 and 0.29, alcohol 0.74 and 0.67, caffeine 0.81 and 0.76, with a median correlation of 0.49 and 0.53. Correlations between the second FFQ and diet recalls were similar. The correlations between the two FFQs as a test of reliability had a median value 0.64 for men and 0.63 for women for selected nutrients. CONCLUSIONS The study suggests that the FFQ method gives acceptable levels of nutrients or food component estimates, as assessed by this calibration study against diet recalls, when limited to energy-adjusted and deattenuated values.

Oxidative balance score and risk of prostate cancer: Results from a case-cohort study

BACKGROUND Prostate cancer is a disease with a complex etiology. Oxidative stress has been implicated in its pathogenesis; however, few prospective studies have investigated the association between an oxidative stress/balance score and risk of prostate cancer. METHODS We investigated associations between an oxidative balance score, calculated as the summation of individual scores obtained from five pro-oxidative and eight anti-oxidative exposures, as well as each individual constituent of the score and risks of prostate cancer overall, and by clinical characteristics, in a case-cohort study (661 cases and 1864 subcohort) nested within the Canadian Study of Diet, Lifestyle, and Health cohort. Men in the lowest quintiles of each pro-oxidant exposure received a score of four (the highest score), while those in the highest quintile received a score of zero (the lowest score). In contrast, scoring for all anti-oxidants was performed in the opposite way. Total oxidative balance score was calculated by summating all individual scores of pro- and anti-oxidative variables, with higher values indicating a higher antioxidant status. RESULTS The average oxidative balance score was similar between prostate cancer cases and men in the subcohort: 25.2 and 25.3, respectively. There was no association between oxidative balance score and overall risk of prostate cancer with hazard ratios (HRs) of 1.00, 1.02, 1.03, 0.97 and 1.01 for increasing quintiles of the score (p-trend=0.71). There were also no associations for non-advanced or advanced disease, or when analysis was restricted to incident cases that arose after two years of follow-up (n=508). In general constituents of the score were not associated with prostate cancer, except for red meat intake (HR=1.44; 95%CI 1.06-1.95 comparing Q5 vs. Q1) and lycopene (HRs of 0.7-0.8 for increasing quintiles). CONCLUSION Our findings do not support an association between oxidative balance score and risks of overall prostate cancer or advanced disease.

Towards ethics guidelines for environmental epidemiologists

Over the past 5 years, several epidemiology organizations have published draft ethics guidelines for epidemiologists in general, without regard to sub-specialty. In this paper, we have reviewed these various guidelines. We have extracted the most salient of the principles from these guidelines and consolidated them into a unified set of ethics guidelines for environmental epidemiologists. Those guidelines found most relevant to environmental epidemiology are those from the Industrial Epidemiology Forum and those from the 1994 Ethics Workshop jointly organized by the International Society for Environmental Epidemiology (ISEE) and the World Health Organization (WHO). From these, core values for those specializing in the field of environmental epidemiology are presented. It is to these core values that the guidelines relate. Additional areas of concern to environmental epidemiologists are noted that guidelines have yet to address. It is emphasized that guidelines require ongoing input from members of the profession and hence are expected to be revised periodically. A discussion of the role and importance of ethics guidelines to environmental epidemiologists within their individual practices, as they relate to one another as colleagues, and as they relate to society at large is included as a preface to the guidelines themselves.

The fluoridation of drinking water and hip fracture hospitalization rates in two Canadian communities.

OBJECTIVES The purpose of this study was to compare hip fracture hospitalization rates between a fluoridated and a non-fluoridated community in Alberta, Canada: Edmonton, which has had fluoridated drinking water since 1967, and Calgary, which considered fluoridation in 1991 but is currently revising this decision. METHODS Case subjects were all individuals aged 45 years or older residing in Edmonton or Calgary who were admitted to hospitals in Alberta between January 1, 1981, and December 31, 1987, and who had a discharge diagnosis of hip fracture. Edmonton rates were compared with Calgary rates, with adjustment for age and sex using the Edmonton population as a standard. RESULTS The hip fracture hospitalization rate for Edmonton from 1981 through 1987 was 2.77 per 1000 person-years. The age-sex standardized rate for Calgary was 2.78 per 1000 person-years. No statistically significant difference was observed in the overall rate, and only minor differences were observed within age and sex subgroups, with the Edmonton rates being higher in males. CONCLUSIONS These findings suggest that fluoridation of drinking water has no impact, neither beneficial nor deleterious, on the risk of hip fracture.