School-age children's safety attitudes, cognitions, knowledge, and injury experiences: how do these relate to their safety practices?

BACKGROUND: A variety of factors affect the safety and risk practices of school-age children, but rarely have multiple factors been considered simultaneously. OBJECTIVE: To examine children's safety attitudes and cognitions more thoroughly and assess how these factors, along with children's safety knowledge and injury experiences, relate to children's safety practices. METHODS: Over several classroom sessions, boys and girls in two age groups (7-9, 10-12 years) completed a psychometrically sound questionnaire that indexes their behaviors, attitudes, cognitions, knowledge, and injury experiences. RESULTS: Fewer safety practices were reported by older than younger children and boys than girls. Children's attitudes, cognitions, knowledge, and injury experiences each correlated with safety practices, but only safety attitudes and injury experiences predicted practices in a multivariate model. CONCLUSION: Exploring the relative influence of numerous factors on safety practices highlights the important role that attitudes play in predicting children's safety practices. Implications of these results for injury prevention programming are discussed.

Cataract surgery rates in Ontario, Canada, from 1992 to 2004: more surgeries with fewer ophthalmologists.

BACKGROUND: To evaluate trends in cataract surgeries in Ontario between 1992 and 2004. METHODS: A retrospective analysis of the number of cataract surgeries performed in Ontario from April 1992 to March 2005. The estimated prevalence of cataract and cataract surgeries per 1000 persons at risk was calculated. RESULTS: The number of cataract surgeries in Ontario increased from 44,943 in 1992 to 109,506 in 2004 (143.6%, 12.08% annual increase). The number of cataract surgeries per 1000 patients at risk of cataract increased from 64.6 in 1992 to 115.65 in 2004 (79%, 4.97% increase per year). This rate was strongly positively correlated with time and with the increase in the Ontario population (r = 0.920 and r = 0.922, respectively; p < 0.001). The number of ophthalmologists increased by 5.3% from 1992 to 1997 and then decreased by 2.9% by 2004. This change was not correlated with the cataract surgery rates (r = 0.475; p = 0.10). However, the number of ophthalmologists per million population decreased by 13.4% between 1992 and 2004. This number had a statistically negative correlation with cataract surgery rates (r = -0.757; p < 0.01). INTERPRETATION: There has been a significant increase in the number of cataract surgeries in Ontario despite a decrease in the number of ophthalmologists per million population.

Compliance in a randomized clinical trial of dietary fat reduction in patients with breast dysplasia.

Dietary compliance was studied in 57 women participating for 1 y in a randomized clinical trial of dietary fat reduction. Nutrient analysis of food records, collected at 0, 6, and 12 mo, was compared with changes observed in lipid profiles and with chemical analysis of duplicate diets. Both food records and duplicate meals showed a significant decrease in fat intake (from 36 to 23% of total calories, p less than 0.0001) and a significant increase in carbohydrate (from 43 to 56% of total calories, p less than 0.0001) in the intervention group. The calculated nutrient intake from food records tended to overestimate the intake of protein, fat, and carbohydrate compared with the chemically analyzed method. The mean level of plasma cholesterol in the intervention group was significantly reduced (7.3%, p less than 0.01) in the first 6 mo after a reduction in dietary fat but the levels observed did not differ significantly between the groups at any time.

Nortriptyline versus amitriptyline in postherpetic neuralgia: a randomized trial.

UNLABELLED: OBJECTIVE (BACKGROUND): Amitriptyline (AT) is a standard therapy for postherpetic neuralgia (PHN). Our hypothesis was that nortriptyline (NT), a noradrenergic metabolite of AT, may be more effective. METHODS: A randomized, double-blind, crossover trial of AT versus NT was conducted in 33 patients. RESULTS: Thirty-one patients completed the trial. Twenty-one of 31 (67.7%) had at least a good response to AT or NT, or both. We found no difference with regard to relief of steady, brief, or skin pain by visual analog scales for pain and pain relief; mood; disability; satisfaction; or preference between the two drugs. Intolerable side effects were more common with AT. Most patients (26/33) were not depressed, and most responding showed no change in rating scales for depression despite the occurrence of pain relief. CONCLUSIONS: We concluded that this study provides a scientific basis for an analgesic action of NT in PHN because pain relief occurred without an antidepressant effect, and that although there were fewer side effects with NT, AT and NT appear to have a similar analgesic action for most individuals.

Pseudooutbreak of Candida guilliermondii fungemia in a neonatal intensive care unit.

During a 3-week period multiple blood cultures obtained from 14 Neonatal Intensive Care Unit infants and 3 Newborn Unit babies grew Candida guilliermondii, a yeast rarely associated with infections in humans. At the time of detection of positive cultures, most infants had been hospitalized for days or weeks for serious perinatal conditions and treated with antibiotics and intravenous hyperalimentation. Two critically ill premature infants from whom the yeast was isolated were given amphotericin B. In 7 other infants, however, yeasts were recovered on the day of birth, raising the question of pseudofungemia. Exhaustive interrogation on the blood culture practices revealed that when drawing blood for a culture from small infants, "butterfly" needles were often flushed with a diluted heparin solution to prevent blood clotting. Culture of a single lot of diluted heparin vials, prepared at the hospital pharmacy and distributed to the Neonatal Intensive Care Unit and Newborn Unit shortly before the onset of the epidemic, grew between 10,000 and 15,000 colony-forming units of Candida guilliermondii/ml. Removal of contaminated heparin vials and discontinuation of heparinization of needles used for blood cultures resulted in cessation of the epidemic. The present outbreak illustrates the difficulties in recognizing pseudoinfections in sick premature infants and the importance of intensive investigation and intervention during such an outbreak.

The use of prophylactic furazolidone to control a nosocomial epidemic of multiply resistant Salmonella typhimurium in pediatric wards.

The nosocomial spread of enteric pathogens is often difficult to control in overcrowded pediatric wards. During 1983 and 1984, despite cohorting of patients and enforced hand washing, more than 200 cases of nosocomial multiply resistant Salmonella typhimurium phage type R-9 were observed on two adjacent pediatric wards. Most cases occurred during the summer months. After 19 new cases were detected early in the summer of 1985, oral administration of furazolidone throughout their entire hospital stay (2.5 mg/kg twice daily) was recommended for all subsequently hospitalized infants. Among the 114 (65%) infants who were appropriately treated, only one additional case (1%) was detected. In contrast 11 (19%) cases occurred among the 59 infants who were inappropriately treated: 5 of 35 (14%) of those who were not treated and 6 of 24 (25%) in whom treatment with furazolidone was delayed greater than 24 hours (P less than 0.001 between the appropriately and inappropriately treated groups). In pediatric wards where infection control measures cannot be optimally applied, prophylactic furazolidone administration may be helpful in preventing the spread of enteric pathogens.

Bicycling exposure and severe injuries in school-age children. A population-based study.

OBJECTIVES: To examine exposure to bicycling and its association with severe bicycle injuries in school-age children in a defined population. DESIGN: Random-digit dialing telephone survey and analysis of hospital discharge records. SETTING: Metropolitan Toronto, Ontario. SUBJECTS: Sample of parents of children aged 5 to 17 years who owned a bicycle; all children who were admitted to hospitals with bicycle-related injuries from April 1989 to March 1991. MAIN OUTCOMES: Median annual bicycling hours and distance by age and sex; age- and sex-specific incidence rates by population at risk, cumulative exposure hours, and riding distances. RESULTS: More than half of the children of all age groups were exposed to bicycling more than 100 hours per year. Boys spent more hours and rode longer distances than girls in every age group. The overall annual injury rates were 8.1 and 3.4 per 10,000 population at risk for boys and girls, respectively. About half of the injuries suffered were head injuries. When rates were estimated on the basis of exposure, boys still experienced a higher injury rate than girls. Boys displayed a slight increase with age in rates per unit of exposure hours. Conversely, age appeared to be negatively associated with overall and head injury rates when exposure was expressed by distance ridden. CONCLUSIONS: Boys had a higher injury rate than girls, and bicycle-related injuries are more likely to be associated with exposure time than distance ridden.

Risk factors for dental fluorosis in a fluoridated community.

We conducted a case-control study to determine the sources of fluoride which are particular risk factors to dental fluorosis. Cases and non-cases were identified by the screening of 8-, 9-, and 10-year-old schoolchildren in the fluoridated community of East York, Ontario. Parents were interviewed about the child's first five years of residence and about diet and preventive caries practices. The Mantel-Haenszel odds ratio and associated chi-square tests were used to assess the association of fluorosis with several potential sources, controlling for other sources of fluoride and mother's education. The prevalence of mild fluorosis [1-4 on the Thylstrup and Fejerskov (1978) Index] was 13%. Those who brushed their teeth before the age of 25 months had 11 times the odds of fluorosis compared with those beginning toothbrushing later; prolonged use of infant formula (greater than or equal to 13 months) was associated with 3.5 times the risk of fluorosis, compared with no, or shorter duration of, formula use. We estimate that these factors were responsible for 72% and 22%, respectively, of the cases in our population. Dental fluorosis is not a public health problem in East York, but parents should be advised to supervise toothbrushing by children under 2 years of age.

A histological comparison in the dog of porous-coated vs. threaded dental implants.

The histological findings of an 18-month trial, in the dog of a partially porous-coated endosseous dental implant made of Ti-6Al-4V, with a truncated conical shape, are described and compared with those for a cylindrical, threaded, endosseous implant made of commercially pure Ti. Six beagle dogs each received two porous-coated implants on one side of the mandible and two threaded implants on the contralateral side. Each set of two implants supported a two-unit fixed bridge for an 18-month functional period. Methylmethacrylate sections of both the buccolingual and mesiodistal aspects of each implant were examined qualitatively and by computer-assisted morphometry. The morphometric measurements were used for determination of the length of implant surface in direct contact with bone on each aspect of each implant. The data were expressed both as an absolute length and as a fraction of the maximum length available for contact (contact length fraction or CLF). On the buccal and lingual aspects of the implants, both the absolute lengths and CLF were significantly smaller for the porous-coated design. For the mesial and distal aspects, the absolute lengths and CLF were less for the porous-coated design, but the differences were not significant. However, when the absolute contact length was related to the corresponding vertical bone height, significant differences were observed, the absolute contact length being greater for any given bone height for the porous-coated design. Taken together, the data suggest that shorter implants may be used with the porous-coated design.

The effect of partial coating with hydroxyapatite on bone remodeling in relation to porous-coated titanium-alloy dental implants in the dog.

For inhibition of crestal bone resorption due to stress shielding and disuse atrophy, an hydroxyapatite (HA) plasma coating was added to the coronal portion of partially porous-coated endosseous dental implants. These implants, as well as control non-HA-coated implants were placed in healed mandibular premolar extraction sites in dogs for a 72-week period of function. Histological examination showed that both implant designs became securely fixed by bone ingrowth into the porous-coated apical region of the implants. The plasma-sprayed HA coating resulted in significantly greater bone height formation and maintenance next to the coronal portion of the implant compared with non-HA-coated implants of similar design. In addition, significant resorption of the 20-to-50-microns-thick plasma-sprayed HA coating occurred over the 18-month period of function.

Clinical outcomes following penetrating keratoplasty using the Barron-Hessburg and Hanna corneal trephination systems.

Two corneal suction trephination systems currently in use are the Barron-Hessburg and the Hanna trephine. This study assessed the outcome of patients who received penetrating keratoplasty using these two systems. One hundred twenty-four eyes (62 with the Hanna system, 62 with the Barron-Hessburg system) from 98 patients undergoing penetrating keratoplasty were evaluated retrospectively. Best corrected spectacle acuity and corneal astigmatism were assessed 6 and 12 months after surgery. No significant difference was noted between the groups 6 months after surgery. At 12 months, a significant improvement in spectacle acuity was present with 55% of the Hanna group having visual acuity of 20/40 or better compared with 33% of the Barron-Hessburg group (p < 0.005). This difference was greater if eyes having the best visual prognoses were separately evaluated: 74% of the Hanna group had 20/40 vision or better compared with 41% of the Barron-Hessburg group (p < 0.005). In eyes having a good visual prognosis, a significant improvement in visual acuity was present, with 33% of the Hanna group improving nine or more lines compared with 9% of the Barron-Hessburg group (p < 0.05). Postoperative keratometric and refractive astigmatism were not different at 6 or 12 months. We found that visual recovery at 1 year is better using the Hanna system, especially in eyes with good visual prognoses.

The prevalence of positive hepatitis B, hepatitis C, and HIV serology in cornea donors prescreened by medical and social history in Ontario, Canada.

PURPOSE: To determine the prevalence of hepatitis B (HBV), hepatitis C (HCV), and human immunodeficiency virus (HIV) in the serum of cornea donors who had been previously screened by social and medical history by the Eye Bank of Canada, Ontario Division. METHOD: A retrospective examination of the donor records of the Eye Bank of Canada, Ontario Division, was conducted. A total of 3,228 records were examined covering the period from May 17, 1993 to May 31, 1996. RESULTS: The prevalence of HBV was determined to be 0.25%, HCV, 0.93%; and HIV, 0.031%. CONCLUSION: The data revealed that despite the use of medical and social history to prescreen, a small percentage of prescreened donors test serologically positive. A comparison of the prevalence of HBV, HCV, and HIV in the prescreened cornea donors to a similarly screened cohort of blood donors over a similar time period reveals a higher prevalence in all three diseases in the cohort of cornea donors. An examination of the demographic characteristics of the population as a whole versus the three groups with confirmed serology failed to show a significant difference between the seropositive and seronegative groups. This study confirms the value and necessity of serologic prescreening of cornea donors as is currently the standard of practice.

Donor eyes. A comparison of characteristics and outcomes for Eye Bank and local tissue.

The Corneal Recipient Registry was begun in 1985 to collect information on all recipients of corneal grafts in the province of Ontario, Canada, and on the donors providing tissue. While most of the tissue is handled by the Eye Bank of Canada (Ontario Division), ophthalmologists in centers away from the Eye Bank often use local tissue when it is available. Comparison of the donor characteristics of local tissue with that obtained through the Eye Bank revealed that local donors were 9-10 years younger (p less than 0.01), their times to enucleation were an hour less (p less than 0.02), and they were much more likely to be the victims of trauma than the donors of Eye Bank eyes. Prognosis of the graft, assessed using life table methods, suggested that success of local eyes was 89% after 6 months, compared with 80% for Eye Bank eyes in the same period, but this was not a significant difference (p greater than 0.05). While the Eye Bank is a more common source of tissue, eyes obtained locally are more likely to represent the "ideal" tissue for many corneal surgeons.

Risk factors for injury: similarities and differences for traffic crashes and other causes.

Actions to prevent injury may address either individual behaviour or population practice. Factors associated with injuries in a variety of circumstances may be best suited to prevention at the level of population whereas more specific causes would not be. Data from the Ontario Health Survey were used to assess the similarities and differences between risk factors and injury in traffic crashes, at work and in other circumstances. Respondents reporting injury were compared with age- and sex-matched controls reporting no injury for reported alcohol ingestion, binge drinking and drinking and driving. In addition, data on the use of licit and illicit drugs, occupation and other demographic factors were compared. Variables showing consistent associations with injury included drug use, some measures of alcohol ingestion and reports of co-existing chronic disease. Many variables showed a variable pattern, including occupation, education and income. In many instances, these differences reflected differences in exposure to risk. Efforts at prevention related to alcohol or medication could be broadly based, whereas for other factors, more targeted prevention efforts would be appropriate.

To drive or not to drive: the influence of social factors on the decisions of elderly drivers.

Being able to drive is considered to be an important, if not vital, component of mobility in many jurisdictions. From a large population-based health survey, carried out in Ontario, Canada in 1990 it is estimated that 37.5% of the population aged 80 or older drives a motor vehicle at least once a year. Data from the survey have been used to make comparisons of drivers and non-drivers: people who drive are more likely to be male, to be married and to report no more than one chronic disease. People who do not drive are more likely to live in larger households and to report two or more chronic diseases. Although many of these factors are clearly related to one another, they exert independent associations with whether people drive after other factors have been controlled. Drivers and non-drivers have similar frequency of contact with family and friends after other variables have been controlled for.

Nonfatal farm injuries in Ontario: a population-based survey.

A population-based mail survey of 2,000 farms was conducted to identify rates and patterns of nonfatal agricultural injury in Ontario. Crude, age-adjusted, and stratum-specific rates of farm injury were calculated using data from the returned questionnaires. Patterns of farm injury and its treatment were described by person, place, and time. Response to the survey was 74% (1,364 of 1,842 farms representing 4,110 farm persons). The crude rate of farm injury was 5.8 per 100 persons per year (95% CI: 5.1, 6.5). Common mechanisms of injury included injuries related to the use of farm machinery, overexertion from lifting, accidental falls, and injuries that occurred while working with farm animals. High injury rates were observed in the male 31-40 age group (12.2 per 100 persons per year). Spouses of farm owner-operators (1.7 per 100 persons per year) and their children (2.0 per 100 persons per year) reported lower rates than expected. Most injured persons attributed no factor or "carelessness" as the principle cause of the injury event. Less than 10% of injuries were reported to the provincial workers' compensation board. We conclude that young adult male farmers have the highest rates of injury and warrant targeting by injury control programs. Data from workers' compensation boards have limited utility in the surveillance of most farm injuries in Ontario, in light of their low rate of reporting. The frequency with which inattention or carelessness is attributed to the injury event (as opposed to environmental factors, which might be changed) suggests that injury control programs must address this gap in understanding among farmers, who clearly are vulnerable to traumatic injury.

Medications as risk factors for farm injury.

A case-control study was used to determine whether cases of farm injury were more likely than controls to have been regularly exposed to certain types of medication including those that cause side effects which may predispose to injury. Persons reporting an injury (n = 176) were identified in a population-based mail survey of people on 1364 Ontario farms, and compared to people without injuries using a 4:1 control: case ratio. Bivariate, stratified, and multivariable analyses were used to quantify the strength of associations between exposures to certain medications and the occurrence of farm injury. Those who regularly used certain types of medication were separated into two groups: people who used the medications in isolation, and those who used the medications in combination with other medications. Response to the survey was 77.3% among cases and 82.6% among controls. Strong and statistically significant increases in risk for injury were observed in association with the regular use of stomach remedies or laxatives by males (OR 2.8; 95% CI: 1.0,7.7), and regular use of heart of circulatory medications by men over the age of 45 (OR 4.2; 95% CI: 1.2,14.7). The identified associations remained after adjustment for age, co-morbidity, tillable farm acreage, education, income, alcohol consumption and tobacco use. Several possible explanations for the occurrence of the identified associations, other than the etiological hypothesis originally advanced, are discussed.

The role of exposure in comparisons of crash risk among different drivers and driving environments.

Crash rates based on drivers, driver-kilometers, and driver-days in the denominator were compared, using survey estimates of time and distance driven and the annual frequency of traffic crashes in Ontario. Rates by age, sex, and region were computed for all crashes and for crashes resulting in injury or fatality. Young male drivers remained at high risk for all types of denominator; older women had high rates when distance was included in the denominator. When time spent driving was substituted, men and women drivers over 60 had very similar rates. For comparisons of rural residents with urban and northern residents, time and distance give equivalent results. These findings suggest that apparent differences in crash risk per kilometre, whether for older women or for urban drivers, is explained by differences in typical driving speed and environment. Exposure time is better than distance to explain crash risk among drivers and regions with very different driving patterns and environments.

Time vs. distance as measures of exposure in driving surveys.

A survey of drivers carried out in Ontario in 1988 has provided data on time spent driving as well as the distances driven for licensed drivers of both sexes in six age groups and three regions. Substantial differences were found in times, distances, and distance/time ratios among these groups. Men drove 50% greater distances, but spent only 30% more time driving than women; speed, averaged over each day's driving, was lower for older drivers than for younger drivers. Differences in speed reflect differences in the driving done in urban or rural areas, and differences in the opportunity for road crashes; such differences, whether based on units of time or distance, will also affect both the comparisons of accident rates and the perceptions of risk among different groups of drivers. A definition of exposure to risk of road crash is required that considers both time and distance appropriately.