Clinical decision rules to improve the detection of adverse drug events in emergency department patients

OBJECTIVES

Adverse drug events (ADEs) are unintended and harmful consequences of medication use. They are associated with high health resource use and cost. Yet, high levels of inaccuracy exist in their identification in clinical practice, with over one-third remaining unidentified in the emergency department (ED). The study objective was to derive clinical decision rules (CDRs) that are sensitive for the detection of ADEs, allowing their systematic identification early in a patient's hospital course.

METHODS

This was a prospective observational cohort study carried out in two Canadian tertiary care hospitals. Participants were adults presenting to the ED having ingested at least one prescription or over-the-counter medication within 2 weeks. Nurses and physicians evaluated patients for standardized clinical findings. A second evaluator performed interobserver assessments of predictor variables in a subset of patients. Pharmacists, who were blinded to the predictor variables, evaluated all patients for ADEs. An independent committee reviewed and adjudicated cases where the ADE assessment was uncertain or the pharmacist's diagnosis differed from the physician's working diagnosis. The primary outcome was an ADE that required a change in medical therapy, diagnostic testing, consultation, or hospital admission. CDRs were derived using kappa coefficients, chi-square statistics, and recursive partitioning.

RESULTS

Among 1,591 patients, 131 (8.2%, 95% confidence interval [CI] = 7.0% to 9.7%) were diagnosed with the primary outcome. The following variables were associated with ADEs and were used to derive two CDRs: 1) presence of comorbid conditions, 2) antibiotic use within 7 days, 3) medication changes within 28 days, 4) age ≥ 80 years, 5) arrival by ambulance, 6) triage acuity, 7) recent hospital admission, 8) renal failure, and 9) use of three or more prescription medications. The more sensitive rule had a sensitivity of 96.7% (95% CI = 91.8% to 98.6%) and required 40.8% (95% CI = 37.7% to 42.9%) of patients to have medication review. The more specific rule had a sensitivity 90.8% (95% CI = 81.4% to 95.7%) and required 28.3% of patients to proceed to medication review.

CONCLUSIONS

The authors derived CDRs that identified patients with ADEs with high sensitivity. These rules may improve the identification of ADEs early in a patient's hospital course while limiting the number of patients requiring a detailed medication review.

Birth outcomes among older mothers in rural versus urban areas: a residence-based approach

PURPOSE

We examined the association between rural residence and birth outcomes in older mothers, the effect of parity on this association, and the trend in adverse birth outcomes in relation to the distance to the nearest hospital with cesarean-section capacity.

METHODS

A population-based retrospective cohort study, including all singleton births to 35+ year-old women in British Columbia (Canada), 1999-2003. We compared birth outcomes in rural versus urban areas, and between 3 distance categories to a hospital (<50, 50-150, >150 km). Outcomes included labor induction, cesarean section, stillbirth, perinatal death, preterm birth (<37 weeks), small-for-gestational-age, large-for-gestational-age, and neonatal intensive care unit admission. We used multivariate regression to obtain adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

FINDINGS

Among the 29,698 subjects, 11.5% lived in rural areas; 5% lived within 50-150 km; and 1.1% lived >150 km from a hospital. Rural women were at lower risk of primary and repeat cesarean section (OR = 0.9, CI: 0.9-1.0; OR = 0.7, CI: 0.6-0.9) and small-for-gestational-age (OR = 0.8, CI: 0.7-0.9) births; they were at increased risk for perinatal death (OR = 1.5, CI: 1.1-2.1) and large-for-gestational-age (OR = 1.1, CI: 1.1-1.2) births. The association was stronger among multiparous versus primiparous women. No differences in emergency cesarean section, preterm birth, or neonatal intensive care admission were found, regardless of parity. Perinatal mortality increased with distance from hospital; OR = 1.5 (CI: 1.1-2.1) per distance category.

CONCLUSIONS

Older women in rural versus urban areas had a lower rate of cesarean section and increased risk of perinatal death. The risk of perinatal death increased with the distance to hospital. Further studies need to evaluate the contribution of underlying perinatal risks, access to care, and decision making regarding referral and transport.

Measure for measure? The challenge of new thinking about patient safety

Penfold and colleagues, in this issue of Healthcare Papers, provide a comprehensive and substantive critique of the hospital standardized mortality ratio (HSMR) as a measure of patient safety, and suggest a useful alternative. However, although measurement is not trivial, new thinking about patient safety presents a much greater challenge than just issues related to measurement. The measurement issue highlights the need for a re-conceptualization of what it takes, from a systems perspective, to achieve safety. This commentary first reviews Penfold et al.'s arguments (agreeing with their conclusions regarding the HSMR). It then presents some key elements of the new thinking about patient safety, particularly the emerging concepts of resilience and resonance, and notes how and why these are beginning to be applied in healthcare. Finally, it considers a number of reasons why a more comprehensive adoption of these new perspectives may be prolonged and notes that, while difficult, the journey is worth taking.

Incidence and demographics of hand fractures in British Columbia, Canada: a population-based study

PURPOSE

To identify population-based hand fracture annual incidence rates, demographics, and seasonal and geographic variations from all patients seeking treatment for a hand fracture in British Columbia, Canada from May 1, 1996 to April 20, 2001.

METHODS

All Medical Service Plan and Hospital Separation records that included International Classification of Diseases-9 codes for metacarpal (815), phalangeal (816), and multiple (817) fractures were extracted from the British Columbia Linked Health Dataset, along with the individual registry demographic records linked to each hand fracture.

RESULTS

A total of 72,481 hand fractures were identified. Fifty percent were phalangeal fractures, 42% were metacarpal fractures, and 8% were multiple fractures. The total population annual incidence rate for a hand fracture was 36 per 10,000. Age-adjusted annual incidence rates ranged from 29 per 10,000 for people older than 20 years to 61 per 10,000 for people age 20 or younger. The most common age for a hand fracture was 14 years for males and 13 years for females. Males had a 2.08 greater relative risk for hand fracture and they maintained most of this increase in risk between the ages of 15 and 40. For females there was an increased relative risk for a hand fracture after the age of 65. Spring had the highest rates for hand fractures. People in the Northern half of the province had a 1.6 greater relative risk for sustaining a hand fracture, compared with people in the more urbanized, less-industrialized, and more-affluent Southwestern region.

CONCLUSIONS

Our study provides a robust projection of annual incidence rates for hand fractures because we were able to review all occurrences of a hand fracture within a population base of approximately 4 million people over a 5-year period. Our study also allowed for the examination of how age, gender, season, and geographic location influenced hand fracture incidence rates within a large, diverse population.

Insulin, macronutrient intake, and physical activity: are potential indicators of insulin resistance associated with mortality from breast cancer?

High levels of insulin have been associated with increased risk of breast cancer, and poorer survival after diagnosis. Data and sera were collected from 603 breast cancer patients, including information on diet and physical activity, medical history, family history, demographic, and reproductive risk factors. These data were analyzed to test the hypothesis that excess insulin and related factors are directly related to mortality after a diagnosis of breast cancer. The cohort was recruited from breast cancer patients treated at the British Columbia Cancer Agency between July 1991 and December 1992. Questionnaire and medical record data were collected at enrollment and outcomes were ascertained by linkage to the BC Cancer Registry after 10 years of follow-up. The primary outcome of interest was breast cancer-specific mortality (n = 112). Lifestyle data were analyzed using Cox proportional hazards regression models to relate risk factors to outcomes, controlling for potential confounders, such as age and stage at diagnosis. Data for biological variables were analyzed as a nested case-control study due to limited serum volumes, with at least one survivor from the same cohort as a control for each breast cancer death, matched on stage and length of follow-up. High levels of insulin were associated with poorer survival for postmenopausal women [odds ratio, 1.9; 95% confidence interval (CI), 0.7-6.6, comparing highest to lowest tertile, P trend = 0.10], while high dietary fat intake was associated with poorer survival for premenopausal women (relative risk, 4.8; 95% CI, 1.3-18.1, comparing highest to lowest quartile). Higher dietary protein intake was associated with better survival for all women (relative risk, 0.4; 95% CI, 0.2-0.8, comparing highest to lowest quartile).

Insulin, Macronutrient Intake, and Physical Activity: Are Potential Indicators of Insulin Resistance Associated with Mortality from Breast Cancer?

High levels of insulin have been associated with increased risk of breast cancer, and poorer survival after diagnosis. Data and sera were collected from 603 breast cancer patients, including information on diet and physical activity, medical history, family history, demographic, and reproductive risk factors. These data were analyzed to test the hypothesis that excess insulin and related factors are directly related to mortality after a diagnosis of breast cancer. The cohort was recruited from breast cancer patients treated at the British Columbia Cancer Agency between July 1991 and December 1992. Questionnaire and medical record data were collected at enrolment and outcomes were ascertained by linkage to the BC Cancer Registry after 10 years of follow-up. The primary outcome of interest was breast cancer-specific mortality (n = 112). Lifestyle data were analyzed using Cox proportional hazards regression models to relate risk factors to outcomes, controlling for potential confounders, such as age and stage at diagnosis. Data for biological variables were analyzed as a nested case-control study due to limited serum volumes, with at least one survivor from the same cohort as a control for each breast cancer death, matched on stage and length of follow-up. High levels of insulin were associated with poorer survival for postmenopausal women [odds ratio, 1.9; 95% confidence interval (CI), 0.7-6.6, comparing highest to lowest tertile, P trend = 0.10], while high dietary fat intake was associated with poorer survival for premenopausal women (relative risk, 4.8; 95% CI, 1.3-18.1, comparing highest to lowest quartile). Higher dietary protein intake was associated with better survival for all women (relative risk, 0.4; 95% CI, 0.2-0.8, comparing highest to lowest quartile).

Beneath the calm surface: the changing face of physician-service use in British Columbia, 1985/86 versus 1996/97

BACKGROUND

Although expenditures on health care are continually increasing and often said to be unsustainable, few studies have examined these trends at the level of services delivered to individual patients. We analyzed trends in the various components that contributed to changes in overall expenditures for physician services in British Columbia from 1985/86 to 1996/97.

METHODS

We obtained data on all fee-for-service payments to physicians in each study year using the British Columbia Linked Health Data set and analyzed these at the level of individual patients. We disaggregated overall billing levels by year into the following components: number of physicians seen by each patient, number of visits per physician, number of services rendered on each visit and average price of those services. We removed the effect of inflation on fees by adjusting to those in 1988. We used direct age-standardization to isolate and measure the effect of demographic changes. We used the Consumer Price Index to determine the effects of inflation.

RESULTS

Total payments to fee-for-service physicians in British Columbia rose 86.3% over the study period. The increase was entirely accounted for by the combined effects of population growth (28.9%), aging (2.1%) and general inflation (41.4%). Service use per capita rose 10.5%; this increase was offset by a decline of 9.4% in inflation-adjusted fees. The average cost of age-adjusted per-capita services rendered by general or family practitioners (GP/FPs) increased very little (3.3%) over the 11-year period, compared with a nearly one-third (31.8%) increase for medical specialists. Although there was a dramatic increase in the number of GP/FPs seen on average by each patient (32.9%), this increase was offset by the combination of decreases in the number of visits per physician (-14.9%), the number of services provided per visit (-8.0%) and the "real cost" of each service provided (-3.5%). Visits to medical specialists increased by about 20% over the study period in all age groups. However, for each person 65 years of age or over receiving any services, the average fee-adjusted expenditures increased 24.8%, almost 4 times the rate of increase for people younger than 65. The use of surgical services grew 26.5% for seniors while declining -2.0% for people under age 65.

INTERPRETATION

These findings suggest a form of "homeostasis" in aggregate-level service use and cost. The supposed inflationary effects of population aging and increasing "abuse of the system" by patients were not found.

Waist-to-hip ratio and breast cancer mortality

High insulin levels have been associated with increased risk of breast cancer and poorer survival after a breast cancer diagnosis. Waist-to-hip ratio (WHR) is a marker for insulin resistance and hyperinsulinemia. In this study, the authors tested the hypothesis that elevated WHR is directly related to breast cancer mortality. For identification of modifiable factors affecting survival, data were collected on 603 patients with incident breast cancer who visited the Vancouver Cancer Centre of the British Columbia Cancer Agency (Vancouver, British Columbia, Canada) in 1991-1992, including body measurements and information on demographic, medical, reproductive, and dietary factors. These patients were followed for up to 10 years. Cox proportional hazards regression models were used to relate the variables to breast cancer mortality (n = 112). After adjustment for age, body mass index, family history, estrogen receptor (ER) status, tumor stage at diagnosis, and systemic treatment (chemotherapy or tamoxifen), WHR was directly related to breast cancer mortality in postmenopausal women (for highest quartile vs. lowest, relative risk = 3.3, 95% confidence interval: 1.1, 10.4) but not in premenopausal women (relative risk = 1.2, 95% confidence interval: 0.4, 3.4). Stratification according to ER status showed that the increased mortality was restricted to ER-positive postmenopausal women. Elevated WHR was confirmed as a predictor of breast cancer mortality, with menopausal status and ER status at diagnosis found to be important modifiers of that relation.

Modified Delphi survey for decision analysis for prophylaxis of post-radiation osteonecrosis

OBJECTIVES

to augment epidemiological data from the literature, assist Bayesian perspectives and a decision analytic framework for the minimization of post-radiation osteonecrosis (PRON; osteoradionecrosis) and its impacts in irradiated head and neck cancer patients.

MATERIALS AND METHODS

a modified Delphi process survey of 15 international clinical experts was used to identify and assess outcome data and factors related to PRON risk, extraction, and factor suitability for formal decision analysis. Clinimetric pain and function outcome scales were created and assessed for relevance to quality of life.

RESULTS AND CONCLUSIONS

expert opinion qualitative assessments were generally adequate and consistent between open- and close-ended items, but many quantitative (e.g. PRON risk rate) estimates were not. A research agenda advocated to validate the epidemiological database for minimization of PRON and decision analysis includes: adoption of a uniform definition of PRON, and ICD code for non-experimental databases; more detailed, consistent data reporting in articles; and quality of life studies.

Carbohydrates and colorectal cancer risk among Chinese in North America

Previous studies have analyzed total carbohydrate as a dietary risk factor for colorectal cancer (CRC) but obtained conflicting results, perhaps attributable in part to the embedded potential confounder, fiber. The aim of this study was to analyze the nonfiber ("effective") carbohydrate component (eCarb) separately and to test the hypothesis that effective carbohydrate consumption is directly related to CRC risk. The data (473 cases and 1192 controls) were from a large, multicenter, case-control study of Chinese residing in North America. Multivariate logistic regression was used to perform a secondary analysis controlling for age; sex; consumption of fat, fiber, calcium, and total kilocalories; body mass (Quetelet's) index; family history; education; and years in North America. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate risk among subgroups by sex and cancer site. A statistically significant positive association was observed between eCarb consumption and risk of CRC in both men (OR, 1.7 comparing highest with lowest tertile of eCarb consumption; 95% CI, 1.1-2.7) and women (OR, 2.7; 95% CI, 1.5-4.8). As expected, the ORs for total carbohydrate were somewhat lower than those for effective carbohydrate, but the differences were not large. A sex difference in risk by colorectal subsite was observed, with risk concentrated in the right colon for women (OR, 6.5; 95% CI, 2.4-18.4) and in the rectum for men (OR, 2.4; 95% CI, 1.2-4.8). These data indicate that increased eCarb and total carbohydrate consumption are both associated with increased risk of CRC in both sexes, and that among women, relative risk appears greatest for the right colon, whereas among men, relative risk appears greatest for the rectum.

The quick and the dead: "managing" inpatient care in British Columbia hospitals, 1969-1995/96

OBJECTIVE

To examine changes in hospital use in British Columbia during a decade of capacity reductions.

DATA SOURCES/STUDY SETTING

The data used are all separation records for British Columbia hospitals for the years 1969, 1978, 1985/86, 1993/94, and 1995/96. Separation records include acute care, rehabilitation, extended care, and surgical day care hospital encounters in British Columbia that were concluded during the years of interest.

STUDY DESIGN

Analyses were based on per capita use of services for five-year age groups of the population to ages 90+; the emphasis was on looking at changes in the use of specific types of hospital services over the 26 years of study, with a particular focus on the most recent decade.

DATA COLLECTION/EXTRACTION METHODS

Data were extracted from hospital separations files owned by the British Columbia Ministry of Health and housed at the Centre for Health Services and Policy Research. All separation records for the years of interest were included in the study.

PRINCIPAL FINDINGS

Acute care use continued to fall over the last decade. The rate of decline increased during the last time period of study and affected seniors to the same degree as younger patients. At the same time, use of extended care decreased, compared to steady increases in earlier years. The result was that by 1995/96 nearly 40 percent of inpatient days were used by people who died in hospital, compared to 9 percent in 1969. These people, however, still represent a small proportion of separations.

CONCLUSIONS

The "bed blocker" problem common to many hospital systems appears to have been largely alleviated in British Columbia over the decade 1985-95. The concurrent decrease in extended care use, however, makes it difficult to say where and how these people are now being cared for. Care for the dying has become a bigger issue for hospitals, but whether this is because of heroic interventions at the end of life is not clear. A "top-down," capacity-driven management approach to hospital use in British Columbia has produced effects that may seem familiar to those involved in more "bottom-up" managed care approaches in the United States.

Hospital downsizing and trends in health care use among elderly people in British Columbia

BACKGROUND

There has been considerable downsizing of acute care services in British Columbia over the past 2 decades. In this population-based study we examined changes in the proportion of elderly people who used acute care, long-term care and home care services between 1986-1988 and 1993-1995 to explore whether the downsizing has influenced use. Changes in death rates were also examined.

METHODS

The British Columbia Linked Health Database was used to select all British Columbia residents aged 65 years, 75-76 years, 85-87 years or 90-93 years as of Jan. 1, 1986 (cohort 1), and Jan. 1, 1993 (cohort 2). Each person was assigned to 1 of 6 mutually exclusive categories of health care use reflecting different intensities of use (i.e., hospital, long-term or home care). The proportions of people within each category were compared between the 2 periods, as were the age-standardized death rates.

RESULTS

There were 79,175 people in cohort 1 and 92,320 in cohort 2. Overall, the relative proportion of people in each use category was similar between the 2 study periods. The most substantial changes were an increase of 2 percentage points in the proportion of people who received no facility or home care services and a decrease of 2 to 3 percentage points in the proportion who received some acute care but no facility-based continuing care. The age-adjusted all-cause death rates for the earlier and later cohorts were virtually identical (15.7% and 15.8% respectively), although the rate increased from 63.6% to 70.1% among those in the "full-time facility with acute care" group.

INTERPRETATION

Overall changes in health care use were small, which suggests that the repercussions of the decline in acute care services for elderly people have been minimal. The higher age-adjusted death rates in the later cohort in full-time care suggests that long-term stays are becoming reserved for a sicker group of elderly people than in the past.

Mortality rates after cataract extraction

Senile cataract may be a marker of generalized tissue aging. We examined this hypothesis using population-based linked health data. We hypothesized that any such association would diminish with increased use of cataract surgery. Mortality rates of those 50-95 years of age undergoing cataract surgery in British Columbia during either 1985 or 1989 were compared with the provincial population of comparable age who did not undergo cataract surgery during the study period. The 1985 cohort included 8,262 patients undergoing surgery and a comparison population of 804,303, and the 1989 cohort included 11,952 patients and a comparison population of 839,393. Using Cox regression, for the 1985 cohort, the hazard ratios for dying during follow-up were 3.2 for males 50-54.9 years of age [95% confidence limits (CL) = 2.0, 5.0] and 3.3 for females (95% CL = 1.9, 5.7). Hazard ratios for older age groups decreased with age. We also fit an additive risk model that produced excess mortalities that were less age dependent. In the 1985 analysis, these ranged from +7.1 per 1,000 (95% CL = +0.44, +13.76) to +20.3 (95% CL = +13.24, +27.36) for males and -17.5 (95% CL = -28.28, -6.72) to +2.0 (95% CL = -2.12, +6.12) for females. Findings for the 1989 analyses were similar, indicating that the association between cataracts and generalized aging remained constant despite a large increase in the use of cataract surgery.

Utilization care plans and effective patient data management

This article introduces the concept of a utilization care plan (UCP) for supporting the communication of data required for effective utilization review and utilization management. Utilization review is a process of measurement that compares the performance of a ward, department, or entire facility against accepted criteria to identify resource use shortfalls. Utilization management is the deliberate action by third party payers to ensure that shortfalls in resource utilization are minimized. Critical to the success of utilization management is effective data communication; utilization review data must be accurate, complete, accessible, timely, and coordinated. Computer-based UCP systems can remind caregivers when and what services should be provided to patients and also monitor the portion of those services that should be administered during each phase of a patient's therapy. Deviations from the UCP system template constitute variances that can be documented and highlighted in a friendly automated system that ensures highly accurate and extremely timely concurrent utilization information. Some implications of using UCP systems for future research and practice are also discussed.

Effectiveness of community-directed diabetes prevention and control in a rural Aboriginal population in British Columbia, Canada

This report presents the process and summative evaluation results from a community-based diabetes prevention and control project implemented in response to the increasing prevalence and impact of non-insulin-dependent diabetes mellitus (NIDDM) in the Canadian Aboriginal population. The 24-month project targeted the registered Indian population in British Columbia's rural Okanagan region. A participatory approach was used to plan strategies by which diabetes could be addressed in ways acceptable and meaningful to the intervention community. The strategies emphasised a combination of changing behaviours and changing environments. The project was quasi-experimental. A single intervention community was matched to two comparison communities. Workers in the intervention community conducted interviews of individuals with or at risk for diabetes during a seven-month pre-intervention phase (n = 59). Qualitative analyses were conducted to yield strategies for intervention. Implementation began in the eighth month of the project. Trend measurements of diabetes risk factors were obtained for 'high-risk' cohorts (persons with or at familial risk for NIDDM) (n = 105). Cohorts were tracked over a 16-month intervention phase, with measurements at baseline, the midpoint and completion of the study. Cross-sectional population surveys of diabetes risk factors were conducted at baseline and the end of the intervention phase (n = 295). Surveys of community systems were conducted three times. The project yielded few changes in quantifiable outcomes. Activation of the intervention community was insufficient to enable individual and collective change through dissemination of quality interventions for diabetes prevention and control. Theory and previous research were not sufficiently integrated with information from pre-intervention interviews. Interacting with these limitations were the short planning and intervention phases, just 8 and 16 months, respectively. The level of penetration of the interventions mounted was too limited to be effective. Attention to process is warranted and to the feasibility of achieving effects within 24 months.

Variation by body mass index and age in waist-to-hip ratio associations with glycemic status in an aboriginal population at risk for type 2 diabetes in British Columbia, Canada

BACKGROUND

It is unclear whether obesity and age modify or confound relations between abdominal adiposity and metabolic risk factors for type 2 diabetes.

OBJECTIVE

Our objective was assess the consistency of relations between abdominal adiposity and glycemic variables across discrete categories of obesity and age.

DESIGN

We performed a stratified analysis of prevalence data from a rural screening initiative in British Columbia, Canada. Subjects were Salishan Indians, all healthy relatives of individuals with type 2 diabetes [n = 151; age: 18-80 y; body mass index (BMI, in kg/m2): 17.0-48.2]. We measured waist-to-hip ratio (WHR) (2 categories); insulin, glycated hemoglobin (Hb A1c), and 2-h glucose concentrations (2 categories); and BMI (4 categories). BMI and age-specific odds ratios (ORs) and 95% CIs were calculated.

RESULTS

WHR-glycemic variable relations were not consistent across BMI and age strata. Risks associated with high WHR were: for persons with BMIs from 25 to 29, elevated insulin (OR: 6.71; 95% CI: 1.41, 34.11) and Hb A1c (OR: 16.23; 95% CI: 2.04, 101.73) concentrations; for persons aged 18-34 y, elevated insulin concentrations [OR: indeterminate (+infinity); 95% CI: 1.89, +infinity]; and, for persons aged 35-49 y, elevated Hb A1c (OR: +infinity; 95% CI: 3.17, +infinity) and 2-h glucose (OR: 9.15; 95% CI: 1.74, 59.91) concentrations.

CONCLUSIONS

WHR discriminates risk of type 2 diabetes in overweight but not obese individuals. Abdominal adiposity is associated with elevated insulin concentrations in younger age groups and with impaired glucose control in middle-aged groups, suggesting metabolic staging by age on a continuum from insulin resistance to impaired glucose tolerance.

Creating a population-based linked health database: a new resource for health services research

As the availability of both health utilization and outcome information becomes increasingly important to health care researchers and policy makers, the ability to link person-specific health data becomes a critical objective. The integration of population-based administrative health databases has been realized in British Columbia by constructing an historical file of all persons registered with the health care system, and by probabilistically linking various program files to this 'coordinating' file. The linkages have achieved a high rate of success in matching service events to person-specific registration records. This success has allowed research projects to be proposed which would otherwise not have been feasible, and has initiated the development of policies and procedures regarding research access to linked data. These policies and procedures include a framework for addressing the ethical issues surrounding data linkage. With continued attention to confidentiality issues, these linked data present a valuable resource for health services research and planning.

Socioeconomic status, mortality, and the development of cataract at a young age

It has been hypothesized that senile cataract may serve as a marker for generalised tissue aging, since structural changes occurring in the proteins of the lens during cataract formation are similar to those which occur elsewhere as part of the aging process. An earlier analysis we carried out to test this hypothesis revealed a strong age-dependent relationship between undergoing cataract surgery and subsequent mortality. Relative risks for dying over 9 yr of follow-up were particularly increased for individuals who had developed cataract requiring operation between the ages of 50-65. This finding prompted us to test the hypothesis that younger patients undergoing surgery for cataract (those in which surgery was undertaken at 50-65 yr of age) would tend disproportionately to be resident in areas of generally lower socioeconomic status. A population-based linked health data resource containing data on all hospital separations in the province of British Columbia was used to examine this hypothesis. Linkage to Canadian census data was used to assign a socioeconomic decile to the area of residence for all individuals in British Columbia who either did, or did not, undergo cataract surgery over a 3 yr period, and were aged 50-95. Relative to those who resided in the highest socioeconomic areas, odds ratios for undergoing cataract surgery between 50 and 65 yr of age were significantly greater than 1 for the four lowest socioeconomic deciles. This association was observed despite a conservative bias in our setting that favoured those of higher socioeconomic status tending to receive earlier treatment. The results of this ecologic study prompt consideration of whether factors which have the dual attributes of being correlates of socioeconomic status and implicated in the development of cataract may play a role in mediating the processes involved in the well known association of socioeconomic status and mortality.

Physicians and breastfeeding: beliefs, knowledge, self-efficacy and counselling practices

A pilot-tested questionnaire was mailed to 325 obstetricians, pediatricians, family practitioners and general practitioners of a British Columbian maternity hospital to measure aspects relating to physicians' attitudes toward breastfeeding counselling. Response rate was 67.3%. The measures of self-efficacy, knowledge and beliefs were added to a regression model containing measures of gender, specialty, years in practice and personal or spousal breastfeeding experience to determine whether additional variance in counselling behaviour could be accounted for. Physicians attempted to convince women to breastfeed if: 1) they believed in the immune properties of breastmilk (OR = 1.23, SE = 0.07) and 2) they were confident in their own breastfeeding counselling (OR = 1.88, SE = 0.36). Likewise, encouraging women to continue breastfeeding in the face of breastfeeding problems was related to confidence in breastfeeding counselling (OR = 1.22, SE = 0.10) and belief in the immune properties of breastmilk (OR = 2.83, SE = 0.45).

Paradigm change and uncertainty about funding of public health research: social and scientific implications

Since the 1970s two fundamental shifts have occurred in health research funding: a reduction in the buying power of research dollars, and an increase in the competition for resources. Most fields have also seen a decrease in the dollars available for research. Pressures for justifying the relevance of research activities have become increasingly pragmatic. The thesis of this paper is that scientific creativity and innovation are compromised by the highly uncertain and competitive funding environment of contemporary health research. This is largely because criteria of scientific excellence predicated on an investigation's presumed future impact support the status quo of methods and subject matter in funded research. Extraordinary rationality among scientists seeking and allocating resources promotes the survival of the existing system over time, yet inhibits progressive development through the transformation of conceptual models. Therefore, despite a growing unrest about the way research on population health is conducted, new conceptions of the relationship between theory and methods have been slow to emerge. Amelioration of a disjunction between the institutionalized rules governing science and the culturally sanctioned goals of science requires commitment to a dialectic between orthodoxy and dissent.

The eyes have it: cataract surgery and changing patterns of outpatient surgery

Health care utilization by the elderly has increased during recent times. However, a number of investigators have indicated that this increase has had less to do with increasing numbers of elders than with increasing age-specific utilization rates for a variety of health services. 1985 and 1993 health data for British Columbia were used to examine changes in outpatient surgical utilization among the general population and changes in cataract surgical utilization among the elderly. Utilization increases in the older persons exceeded what would be expected on the basis of population increase. Furthermore, cataract surgery alone accounted for more than 29 percent of the entire utilization increase observed for outpatient surgery. Despite this increase, the average age at cataract surgery has not changed—seniors of all ages are much more likely to receive cataract surgery now than a decade ago. The authors' findings suggest that a part of this observed increase is due to operating on individuals at preoperative levels of better visual function.

Field trial of the Otago photoscreener

OBJECTIVE

To assess the effectiveness of the Otago photoscreener in detecting amblyogenic factors in the general population.

DESIGN

Prospective clinical trial.

SETTING

Suburban school district in Delta, BC.

PARTICIPANTS

A total of 1245 kindergarten children.

INTERVENTIONS

Screening for visual defects was done with the Otago photoscreener (by a technician) and the regular manual method (by a health care aide). A standard ophthalmologic examination was performed by a pediatric ophthalmologist and an orthoptist in a random sample of 20% of all children with normal results of screening (n = 241) plus all those with abnormal results (n = 29).

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive predictive value, rates of false-negative and false-positive results.

RESULTS

The Otago screener had higher sensitivity than the manual technique (81% vs. 33%), especially for strabismus and cataracts. The specificity values of the two techniques were 98% and 97% respectively, and the positive predictive values were 77% and 54% respectively. The manual technique failed to identify 5.8% of children with visual defects, compared with 1.6% for the Otago screener.

CONCLUSIONS

The Otago photoscreener is a superior instrument for identifying amblyogenic eye disease. However, given the relatively low yield, the value of any screening method should be assessed with regard to both costs and benefits.

Research methods for surgeons: an overview

The purpose of this paper is to outline a number of salient features in the design and conduct of clinical research in surgery. The key features emphasized are the need for clarity in the elaboration of study hypotheses, clear definition of the variables involved in the study, particularly the outcome variables, the need to confront the issue of bias and confounding, and a review of methodological issues associated with specific components in the research process. Particular attention is paid to patient selection, allocation of patients to experimental and control groups, randomization, problems of co-intervention and contamination, a brief discussion of analytic issues, and the critical importance of getting appropriate design and other methodological assistance prior to initiating a study. A short bibliography providing the reader with more in-depth discussions of the issues raised here is provided. It is the intention of this paper to introduce surgeons undertaking clinical research to these important methodological issues so that they can utilize appropriate consultative services more effectively.

The psychological consequences of predictive testing for Huntington's disease. Canadian Collaborative Study of Predictive Testing

BACKGROUND

Advances in molecular genetics have led to the development of tests that can predict the risk of inheriting the genes for several adult-onset diseases. However, the psychological consequences of such testing are not well understood.

METHODS

The 135 participants in the Canadian program of genetic testing to predict the risk of Huntington's disease were followed prospectively in three groups according to their test results: the increased-risk group (37 participants), the decreased-risk group (58 participants), and the group with no change in risk (the no-change group) (40 participants). All the participants received counseling before and after testing. Standard measures of psychological distress (the General Severity Index of the Symptom Check List 90-R), depression (the Beck Depression Inventory), and well-being (the General Well-Being Scale) were administered before genetic testing and again at intervals of 7 to 10 days, 6 months, and 12 months after the participants received their test results.

RESULTS

At each follow-up assessment, the decreased-risk group had lower scores for distress than before testing (P < 0.001). The increased-risk group showed no significant change from base line on any follow-up measure, but over the year of study there were small linear declines (P < 0.023) for distress and depression. The no-change group had scores lower than at base line on the index of general well-being at each follow-up (P < or = 0.045). At the 12-month follow-up, both the increased-risk group and the decreased-risk group had lower scores for depression and higher scores for well-being than the no-change group (P < or = 0.049).

CONCLUSIONS

Predictive testing for Huntington's disease has potential benefits for the psychological health of persons who receive results that indicate either an increase or a decrease in the risk of inheriting the gene for the disease.

The merits of confidence intervals relative to hypothesis testing

A variety of statistical tests of a null hypothesis commonly are used in biomedical studies. While these tests are the mainstay for justifying inferences drawn from data, they have important limitations. This report discusses the relative merits of two different approaches to data analysis and display, and recommends the use of confidence intervals rather than classic hypothesis testing.

Formulae for a confidence interval surrounding the point estimate of an average value take the form: d= ±zσ/√n, where “d” represents the average difference between central and extreme values, “z” is derived from the density function of a known distribution, and “a/-∨n” represents the magnitude of sampling variability. Transposition of terms yields the familiar formula for hypothesis testing of normally distributed data (without applying the finite population correction factor): z = d/(σ/√n).

Utilization management: a literature review for Canadian health care administrators

Utilization management (UM), the attempt to measure, understand and reduce inappropriate hospital use, has been in development for over 20 years. It is an outgrowth of two related phenomena: (1) the increasing responsibility of large institutional third party payers for health care costs and the increasing demand of those payers for accountability; and (2) in Canada, particularly, the debate surrounding the adequacy of hospital funding and the perceived inadequacy of cost control using global budgeting. Given the interest in UM, hospital administrators, provincial and federal associations representing hospitals, hospital employees and physicians would find a review of UM programs useful in terms of what is known about their effectiveness, and the specific initiatives in Canada. The authors underscore the critical need for formal evaluation of UM programs; to date there has been little systematic research into issues related to its implementation and impact. This issue is particularly pertinent because UM programs have not been widely implemented in Canada.

Anemia in pediatric day-surgery patients: prevalence and detection

A prospective study was conducted to determine the prevalence of anemia in pediatric day-surgery patients, and a single-blinded study was conducted to evaluate the anesthesiologist's capability to detect preoperative anemia clinically. The subsequent management of children with anemia was noted. During the preoperative examination the anesthesiologist completed a questionnaire and predicted the preoperative hemoglobin concentration based on the history and physical examination. The preoperative hemoglobin concentration was measured for all of the patients, but the results were withheld until after completion of the questionnaire. Documentation was complete in 2,649 patients, and these comprised the final study group. Fourteen patients (0.5%) were anemic (hemoglobin concentration less than 100 g/l), but of these, only 5 had been predicted to be anemic based on clinical examination. Seven of these 14 anemic patients were less than 1 yr of age. Only 2 of the anemic patients had surgery postponed, and 1 of these also had a respiratory infection. Forty-four patients were incorrectly predicted to be anemic (i.e., their actual hemoglobin concentration was greater than 100 g/l). We conclude that in our patients, anemia is rare but is more likely to occur in those less than 1 yr of age. The presence of mild degrees of anemia does not alter the decision to proceed with day surgery. The anesthesiologists participating in this study could not reliably detect anemia clinically.

Hospital-based utilization management: a cross-Canada survey

Utilization management attempts to measure, understand and, when appropriate, reduce hospital use. We conducted a telephone survey to determine the status of utilization management in Canadian hospitals. The sample comprised a random selection of 30% of acute-care hospitals with over 100 beds for adults in Ontario and Quebec and all such hospitals in the other provinces. Of the 123 chief executive officers contacted 99 (80%) claimed to have a utilization management program. Of those, 90 (91%) agreed to participate in an in-depth survey or to designate a senior administrator to be interviewed who was most knowledgeable about the program. High occupancy rates and funding issues were the most common environmental triggers for the development of utilization management programs; funding issues were listed more frequently by respondents in Ontario than by those elsewhere (p = 0.0008). Retrospective review alone was used in half of the hospitals, concurrent review or some mixed approach being used in the other half. Ontario and the Atlantic provinces were more reliant than the rest of the country on retrospective review alone (p = 0.0032). Most of the hospitals used peer review and education to stimulate corrective action. Of the respondents 67% indicated that the medical staff supported the utilization management program, and 53% reported that the program had a positive impact on the relationship between administrative and medical staff. Most of the respondents were unsure of the program's impact on the quality of care or the rate of unnecessary hospital admission. However, retrospective review alone was found to be less successful in reducing inappropriate utilization than either concurrent review or combined review (p = 0.0048).

Retinopathy of prematurity-induced blindness: birth weight-specific survival and the new epidemic

A recent population-based study in the Canadian province of British Columbia showed that, since the mid-1960s, there has been a significant increase in the incidence of retinopathy of prematurity-induced blindness in infants weighing 750 to 999 g at birth. To determine the impact of changing birth weight-specific survival on this new epidemic, all infants born in the province in the period 1952 through 1986 and known to the British Columbia Health Surveillance Registry as having retinopathy of prematurity-induced blindness were identified. In addition, the birth registration records for the 1,299 740 infants born in British Columbia in the same period and the death records of the 22,940 British Columbia-born infants who died in the province before the end of their first year of life were linked using a combination of probabilistic and manual record linkage techniques. These linked records and the records from the Health Surveillance Registry were used to calculate birth weight-specific incidence rates of retinopathy of prematurity-induced blindness in liveborn infants and first-year-of-life survivors. The rates, in 5-year intervals, showed that, in both liveborn infants and first-year survivors, the highest birth weight-specific rates occurred during the first epidemic of retinopathy of prematurity, which ended in British Columbia in 1954. Since the mid-to late-1960s, the incidence of retinopathy of prematurity-induced blindness in liveborn infants weighing less than 1000 g increased steadily whereas in infants weighting 1000 to 1499 g, incidence decreased slightly since the original epidemic ended. However, the experience of first-year-of-life survivors is substantially different.(ABSTRACT TRUNCATED AT 250 WORDS)

Episiotomy in low-risk deliveries: physician factors

From 376 randomly selected nulliparous women who delivered at the Grace Hospital in 1986, we selected 133 low-risk women and performed a retrospective chart review to ascertain the episiotomy rate for physicians by sex, years since graduation, and specialty status. There was a statistically significant difference between the rate for specialists (65%) and general practitioners (38%). A non-significant difference was found between male physicians (41%) and female physicians (56%) and between physicians who had graduated within 15 years (42%) and those who graduated more than 15 years ago (52%). Subgroup analysis of the general practitioner data revealed different patterns for male and female physicians according to their graduation cohort.

A trial of desmopressin (1-desamino-8-D-arginine vasopressin) to reduce blood loss in uncomplicated cardiac surgery

Previous studies have suggested that desmopressin may reduce the bleeding diathesis that often complicates open-heart surgery. To pursue this question further, we performed a double-blind, randomized, placebo-controlled trial to determine whether the previously reported beneficial effect of desmopressin on hemostasis during complex cardiac surgery was applicable to all elective cardiac surgical procedures involving cardiopulmonary bypass. In 150 consecutive patients, most of whom underwent primary coronary-artery bypass grafting, we compared the effects of intravenous desmopressin (0.3 microgram per kilogram of body weight) with those of saline placebo on postoperative blood loss and the need to replace blood products. The median amount of blood lost within the first 24 hours after operation was similar in the desmopressin and placebo groups (865 vs. 738 ml; P = 0.26). The postoperative use of blood replacement products did not differ significantly between the groups (1025 ml [95 percent confidence interval, 300 to 4140 ml] in the desmopressin group and 860 ml [247 to 5346 ml] in the placebo group). Desmopressin is believed to exert its hemostatic effect by releasing von Willebrand factor. The level of ristocetin cofactor, a functional index of the level of von Willebrand factor, was increased approximately twofold from base line in both treatment groups 90 minutes and 24 hours after the administration of medication. Similarly, the levels of von Willebrand factor multimers increased uniformly in both groups. These findings may be consistent with a normal stress response of von Willebrand factor to major surgery and could explain our failure to detect a therapeutic effect of desmopressin. We conclude that the majority of patients who undergo elective cardiac surgery receive no hemostatic benefit from the use of desmopressin.

Randomized, double-blind, controlled trial of long-term diuretic therapy for bronchopulmonary dysplasia

The effects of continuous therapy with hydrochlorothiazide and spironolactone on pulmonary function in 34 premature infants with severe bronchopulmonary dysplasia were assessed in a randomized double-blind controlled trial. Subjects were greater than or equal to 30 days old, were supported by mechanical ventilation in greater than or equal to 30% oxygen, and had radiographic evidence of bronchopulmonary dysplasia. The treatment group (n = 19) and the placebo group (n = 15) were similar in all respects except for distribution of gender. Anthropometrics, ventilatory measurements, and the results of pulmonary function tests were evaluated at study entry and at 1, 4, and 8 weeks into therapy. Poststudy chest radiographs were compared with those obtained before the study. The proportion of infants alive at discharge was significantly increased (84%) in the treatment group compared with the placebo group (47%) (p = 0.05). There were no statistically significant differences in total hospital days or in total ventilator days. Total respiratory system compliance at 4 weeks was higher in the treatment group (0.61 +/- 0.18) than in the placebo group (0.45 +/- 0.13) (p = 0.016). No difference in outcome was detected between male and female infants in the treatment group. These results suggest that long-term diuretic therapy improves outcome in infants with bronchopulmonary dysplasia.

A comparison of photoscreening techniques for amblyogenic factors in children

We screened 236 consecutive patients aged 6 years or less using an Off-Axis photoscreener and an Otago-type photoscreener. With a masked standardized clinical assessment as the standard, an overall comparison of the results obtained with the two techniques revealed a sensitivity and specificity in the neighbourhood of 0.85 and 0.87 respectively for the Off-Axis photoscreener and 0.94 and 0.94 respectively for the Otago photoscreener. Both techniques, but especially the Off-Axis technique, were less sensitive and specific in younger children (24 months or less). Fundus colour (light or dark) did not greatly affect sensitivity or specificity. Photoscreening with the pupil dilated led to an increase in false-positive results with both techniques. Our results showed the Otago photoscreener to be superior in this clinical trial.

Practice patterns of family physicians with 2-year residency v. 1-year internship training: do both roads lead to Rome?

Are there differences in patterns of practice between actively practising physicians who have been certified after a 2-year family practice residency and matched physicians without certification who have completed the standard 1-year internship? With the use of billing files prepared by the British Columbia Medical Association a group of 65 family practice certificants in active practice in British Columbia was compared with a control group of 130 internship trainees matched by year and school of graduation, category of billing (i.e., solo or group) and region. A wide range of practice features was assessed for the fiscal years 1984-85, 1985-86 and 1986-87. No differences were detected between the groups in 1986-87 for the following practice variables: number of patients (1888 and 1842 respectively), number of personal services billed for (7265 and 7173), number of personal services per patient (3.9), amount of funding for personal services ($140,192 and $140,100) and amount per patient for personal services ($77 and $79). Age-adjusted costs for male and female patients were similar in the two groups. Of six services thought to be influenced by type of training, only maternity care generated a significantly higher number of billings in the study group (341 v. 249). These results suggest that there is no demonstrable effect of training on patterns of practice. However, the question of the effect of training on quality of care and whether the 2-year residency may have a longer effect on practice patterns should be the focus of future research.

Retinopathy of prematurity: a new epidemic?

This study provides the first empiric evidence for the existence of a new epidemic of retinopathy of prematurity-induced blindness. Data from a population-based register of handicapping conditions in the Canadian province of British Columbia, and a birth weight-specific census of live-born infants in British Columbia, were used to determine annual, population-level incidences of retinopathy of prematurity-induced blindness during 1952 to 1983. Changes in incidence since the end of the original epidemic (1954) were determined by subdividing the 29-year period (1955 to 1983) into two intervals (1955 to 1964 and 1965 to 1983). Standardized incidence ratio analyses revealed a marginally significant increase in the overall incidence of retinopathy of prematurity-induced blindness in the later as compared with the earlier period. Infants weighing 750 to 999 g at birth had a significantly increased standardized incidence ratio of 3.07 (95% confidence interval 1.26, 11.06). No increases in risk were observed in heavier or lighter weight infants. Because ascertainment and diagnostic changes do not explain the weight-specific increases in incidence, these results provide the first population-level evidence for a new epidemic.

Evaluation of a postocclusive reactive circulatory hyperaemia (PORCH) test for the assessment of ulnar collateral circulation

This prospective double-blind study compared Doppler assessment of the ulnar collateral circulation with the Allen's test and a postocclusive reactive circulatory hyperaemia (PORCH) test in 144 patients (288 hands). The PORCH test involves inflation of a blood pressure cuff on the upper arm to a supra systolic (+50 mmHg) pressure for two minutes. Prior to cuff deflation, both radial and ulnar arteries are occluded at the wrist; the cuff is then deflated and a 15-second period allowed so as to restore blood flow down to the wrist. Ulnar artery compression is now released and the time to revascularization measured. Fifty-eight per cent of hands with an abnormal Allen's test had a normal ulnar collateral circulation. Results of Allen's test were not significantly affected by patients' sex or smoking status (p greater than 0.1) but there was a significant difference (p = 0.001) in the false positive rates between patients over 40 years of age (0.2) and those under 40 years of age (0.03). Results of the PORCH test were not significantly affected by patients' age, sex or smoking status (p greater than 0.1). With a revascularisation time of 19 sec as a "cut off" for ulnar abnormality the PORCH test, unlike the Allen's test, was perfectly predictive of an abnormal ulnar collateral circulation and had no false positives.

The assessment of diagnostic tests: a comparison of medical literature in 1982 and 1985

To determine whether improvements have occurred since a survey of the 1982 literature assessing diagnostic tests, the authors evaluated all English-language articles that assessed clinical diagnostic tests in abridged Index Medicus journals in 1985, and that had the terms sensitivity and specificity in the title, abstract, or key words. The 89 articles were assessed against seven methodologic criteria, including use of a well-defined "gold standard," clearly defined test interpretation, blinding, clear data presentation, correct use of sensitivity and specificity, calculation of predictive values, and consideration of prevalence. In comparisons of 1985 vs. 1982 articles, there were significant improvements in five of the seven criteria. For example, the proportion of articles using a well-defined "gold standard" rose from 68% to 88%. Overall, the frequency of papers demonstrating five or more of the seven criteria increased from 26% to 47%. However, predictive values were discussed in only 54% of the articles without, necessarily, consideration of the influence of prevalence as well. This study raises the concern that while the concepts of sensitivity and specificity are now accepted, predictive values remain less well understood. Although there has been an improvement in the assessment of diagnostic tests in published research, attention to accepted methodologic standards is still needed on the part of researchers, reviewers, and editors.

Prenatal care: a comparative evaluation of nurse-midwives and family physicians

We evaluated the prenatal care provided to 44 low-risk women by nurse-midwives (NMs) at a special clinic of a large obstetric referral hospital and a sample of 88 low-risk women attended by family physicians (FPs) in their offices. The women were matched on the basis of date of delivery, age, parity, number of previous miscarriages, gravidity, socioeconomic status and delivery after 32 weeks' gestation. The Burlington Randomized Controlled Trial criteria, which reflect community standards of care, were updated and used to assess the information, which was provided on standard provincial prenatal care forms. Scoring was carried out blindly, and interrater reliability was high. A highly significant difference was found in the proportions of NM and FP charts that were rated adequate, superior or inadequate: 77% v. 24%, 7% v. 16% and 16% v. 60% respectively. The rate at which procedures were omitted (leading to an inadequate score) in the categories of initial assessment, monitoring and management also varied between the two patient groups. These findings, even when considered in terms of several biases that may have resulted in the high proportion of NM charts rated at least adequate, suggest that NMs provide prenatal care to low-risk women that is comparable, if not superior, to the care provided by FPs.

The epidemiology of school injuries: the problem of measuring injury severity

In the few surveys of injuries occurring in schools, severity has been defined using a priori criteria based on the nature of injury and by the area injured. The validity of these methods of classifying injury severity has not been established. The association between two commonly used measures of injury severity (nature of injury and body area injured) with referral to medical assessment was explored, based on a simple model derived from the literature. Kendalls Tau-b was used to assess the association between the indicators of injury severity and referral; controlled for both school level (elementary school and secondary school) and the degree of behavioural control that could be exerted in the location of the injury. There was a very low association between indices of injury severity and referral for medical assessment regardless of level of school or degree of behavioural control. It is concluded that the simple model derived from the literature does not adequately describe the relationship between injury severity and referral in the school setting. The major issue facing school staff is not the measurement of injury severity per se, but the appropriate referral of the injured child for medical assessment and treatment.

Prison health services: a utilization study

A prospective study of health service utilization carried out in the Correctional Services of Canada (CSC), Pacific Region, is reported. Health service encounters occurring at the six Regional Institutions with on-site health care centers between May 29th and June 28th, 1984 were surveyed using a health clinic encounter form. There were 7,449 encounters during the study period. The mean rate of encounters was 5.2 per inmate. Seventy-two percent of these encounters occurred at wickets, and 28% occurred at clinics. Physician visits occurred at a mean estimated annual rate of 6.7 visits per year. This is 2.4 times higher than the mean annual physician visit rate for non-institutionalized men in Canada. The reason for visits was new illness (57%), chronic illness (31%), injuries (5%), psychosocial problems (2%), and administrative (5%). The encounter rate per 100 inmates varied from 19.7 to 1,203.6 across the institutions studied. Overall 89% of all visits were seen by health service nurses, while 11% were seen by physicians. Using ICHPPC-2 Defined, the ten most common complaints presented to the health service were headache, sore throat, stomach complaint, other respiratory complaint, tension headache, limb pain, other/not codable, medical examination, back pain and upper respiratory tract infection. These ten complaints accounted for 4896 (59%) of the total complaints recorded. The majority of visits took less than five minutes, were most often treated with medication, and did not require scheduled follow-up. The 50 most frequent visitors, those making 25 or more visits during the study period, while only 3.5% of the study population, accounted for 25% of all encounters.

Epidemiology of school injuries: a 2-year experience in a municipal health department

School injuries occurring in a municipal school system during a 2-year period were reviewed to identify epidemiologic features of school injuries, to determine data requirements for ongoing injury surveillance, and to identify potential preventive strategies. Overall, 3,009 injuries were reported (2.82/100 students per year). Elementary school students had only a slightly higher rate (2.85) than secondary school students (2.78). However, the cause, nature, school location of injury, and body area injured formed distinct patterns in these two groups. Playgrounds were responsible for the highest overall and elementary school rates, whereas sports areas and classrooms had the highest rates among secondary school students. Falls were the most frequent cause of injury in elementary schools whereas, as expected, sports injuries were the most frequent cause among secondary school students. Contusions and abrasions of the head were the most frequent type of injury for both groups, although more common among elementary school students, whereas fractures, sprains, strains, and dislocations were more frequent among secondary school students. Although the proportion of severe injuries to secondary school students was slightly higher (39 v 35%), the rate of referral of students to a hospital or physicians among secondary school students (1.21 per 100 student-hours) was almost twice the rate of elementary school students (0.65 per 100 student-hours). Problems with definition of injury severity and the need to explore the social aspects of schools as a factor in injuries emerged as important considerations for future research.