Education of women about the prevention of preterm birth.

OBJECTIVES: To describe: 1) The education of pregnant women by health care professionals about the prevention of preterm birth; and 2) professionals' views about future initiatives. BACKGROUND: A population survey of health professionals was conducted in Eastern Ontario. The response rate was 73% (608/835). RESULTS: Education materials for women receiving prenatal care about the prevention of preterm birth were available from 10% (12/115) of family physicians, 40% (23/58) of obstetricians, 19% (57/306) of labour room nurses and 76% (94/124) of the prenatal teachers. Only one third of physicians routinely discussed the signs and symptoms of preterm labour prior to 20 weeks. Practitioners' future priorities were smoking cessation programs for pregnant women and increased attendance at early prenatal classes. CONCLUSIONS: Most women are not being educated by anyone in the health care team about the prevention of preterm birth. There is a need for multidisciplinary guidelines about the timing and type of information for women about risk reduction and the early identification and treatment of preterm labour.

Association of cisplatin nephrotoxicity with patient characteristics and cisplatin administration methods.

OBJECTIVE: To assess factors that affect cisplatin nephrotoxicity. METHODS: In 425 patients treated with cisplatin, we assessed the effect of pretreatment factors and treatment conditions on the rise in serum creatinine with the first course of cisplatin, on the maximum rise in serum creatinine over the entire course of the cisplatin therapy, and on residual nephrotoxicity after the last cisplatin treatment ended. (Because of the nature of the relationship between serum creatinine and creatinine clearance, rise in serum creatinine was divided by pretreatment creatinine squared.) Patients were dichotomized into the upper quartile versus the lower three quartiles of degree of nephrotoxicity. Multivariate analyses were based on logistic regression, controlling for cisplatin dose per course. RESULTS: Controlling for cisplatin dose per course, factors most closely associated with nephrotoxicity during the first course of cisplatin were: serum albumin and potassium, body surface area, and administration of cisplatin over 2-5 days per course vs 1 day (negative associations). Controlling for cisplatin dose per course, the single factor most closely associated with maximum life-time cisplatin nephrotoxicity was concurrent use of a vinca alkaloid (negative association). Controlling for cisplatin dose per course, factors most closely associated with residual nephrotoxicity after the end of cisplatin therapy were cumulative dose of cisplatin, concurrent use of metoclopramide (positive associations), uric acid and concurrent use of phenytoin and a vinca alkaloid (negative associations). The association of nephrotoxicity with uric acid and with body surface area was felt to be an artifact resulting from its positive association with pretreatment serum creatinine. Nephrotoxicity during the first course of cisplatin also correlated significantly with autopsy kidney cortex platinum concentrations in 77 evaluable patients. CONCLUSIONS: (1) While several factors correlated with cisplatin nephrotoxicity, most of the observed nephrotoxicity was not explained by the variables identified. (2) While most patients received intravenous hydration, patients receiving high hydration volumes did not have significantly less nephrotoxicity than patients receiving lower hydration volumes: (3) Of the variables identified, serum albumin, metoclopramide and phenytoin may have affected nephrotoxicity by altering cisplatin uptake into or distribution within the kidney.

Statistical power, sample size, and their reporting in randomized controlled trials.

OBJECTIVE: To describe the pattern over time in the level of statistical power and the reporting of sample size calculations in published randomized controlled trials (RCTs) with negative results. DESIGN: Our study was a descriptive survey. Power to detect 25% and 50% relative differences was calculated for the subset of trials with negative results in which a simple two-group parallel design was used. Criteria were developed both to classify trial results as positive or negative and to identify the primary outcomes. Power calculations were based on results from the primary outcomes reported in the trials. POPULATION: We reviewed all 383 RCTs published in JAMA, Lancet, and the New England Journal of Medicine in 1975, 1980, 1985, and 1990. RESULTS: Twenty-seven percent of the 383 RCTs (n = 102) were classified as having negative results. The number of published RCTs more than doubled from 1975 to 1990, with the proportion of trials with negative results remaining fairly stable. Of the simple two-group parallel design trials having negative results with dichotomous or continuous primary outcomes (n = 70), only 16% and 36% had sufficient statistical power (80%) to detect a 25% or 50% relative difference, respectively. These percentages did not consistently increase over time. Overall, only 32% of the trials with negative results reported sample size calculations, but the percentage doing so has improved over time from 0% in 1975 to 43% in 1990. Only 20 of the 102 reports made any statement related to the clinical significance of the observed differences. CONCLUSIONS: Most trials with negative results did not have large enough sample sizes to detect a 25% or a 50% relative difference. This result has not changed over time. Few trials discussed whether the observed differences were clinically important. There are important reasons to change this practice. The reporting of statistical power and sample size also needs to be improved.

Effectiveness of a pregnancy smoking cessation program.

OBJECTIVE: To evaluate two nursing approaches to promoting smoking cessation during initial antenatal visits. DESIGN: Experimental, with assignment to interventions using a random, alternate-day strategy and blind assessment of smoking at baseline, 1 month postintervention, 36 weeks' gestation, and 6 weeks postpartum. SETTING/PARTICIPANTS: 224 daily smokers, fewer than 31 weeks gestation, during first prenatal visit, at a teaching hospital antenatal clinic. INTERVENTIONS: An evening class providing guidance on a self-help program for 2 hours on a group basis or 20 minutes on an individual basis during the prenatal appointment. MAIN OUTCOME MEASURE: Smoking cessation, confirmed by urinary cotinine levels. RESULTS: All women assigned to the referral intervention received a referral, but none attended the classes. In contrast, 93% assigned to the immediate intervention received the intervention. The group receiving immediate intervention had two to three times higher rates of cessation at all follow-up periods, with significant differences at the 1-month follow-up. There were certain similarities between the groups. CONCLUSION: Cessation interventions should be administered during the first prenatal visit.

Low-cost hepatitis B vaccine improves uptake among self-paying health-care students.

Advisory committees recommend hepatitis B (HBV) immunization for professional and student health-care workers. However, the currently licensed vaccines are expensive, and previous surveys have shown that few students (14%) have been immunized in Canada. A low-cost immunization program was offered to health-care students in order to determine whether the effectiveness of HBV immunization could be improved by substantially reducing the vaccine cost to recipients. The immunogenicity, side effects, and 3-dose completion rate of a low-cost Korean HBV vaccine were compared with a similar U.S.-made vaccine. A total of 922 postsecondary students enrolled in 6 health-care disciplines in Ottawa, Canada were surveyed for hepatitis-B immunization status. Nonimmunized students were subsequently offered HBV vaccine at total cost of $15 (Canadian), randomly allocated to receive 3 intramuscular doses of either Korean or U.S.-made plasma-derived HBV vaccine in a double-blind fashion, surveyed about side effects, and tested for hepatitis B surface antibody seroconversion. Only 12% of the 922 surveyed students had been previously immunized when vaccine was obtainable only at high cost. However, 66% of those not immunized participated in the vaccine trial and paid the $15 fee. Hepatitis-B surface antibody seroconversion (greater than or equal to 10 sample ratio units by radioimmunoassay) occurred in 291/311 (93.6%) and 299/310 (96.5%) of recipients of 3 doses of the Korean and U.S. vaccines, respectively (P = 0.10). There were no meaningful differences in vaccine adverse effects, and 92.6% of recipients of either vaccine completed 3 doses.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of the "Time to Quit" self-help smoking cessation program.

Public health and hospital nurses have widespread contact with smokers; an effective smoking cessation program administered by nurses has tremendous potential. This study evaluated: 1) the effectiveness of the self-help cessation program, "Time to Quit"/"Moi aussi, j'écrase" (TTQ), provided on a one-to-one basis; and 2) a smoking cessation training program for baccalaureate nursing students. Nursing students recruited 307 smokers who were randomly assigned to receive one of two interventions. Control smokers received a list of community smoking cessation resources and experimental subjects received this list plus TTQ. Smoking self-reports and cotinine levels were obtained at baseline, six weeks and nine months. More smokers receiving TTQ had reduced at six weeks post-intervention, while there were no differences in quit or reduction rates at the nine-month follow-up. Students were positive about learning the techniques and their knowledge scores were significantly higher than those of non-participating students.

Characteristics of children presenting with chest pain to a pediatric emergency department.

Chest pain among children is a common complaint in primary care practice. However, the demographic features and treatment of such patients are controversial. We distributed a questionnaire to 336 consecutive patients with a complaint of chest pain seen during 1 year at an urban pediatric emergency department. Such visits represented 0.6% of all emergency encounters; the male:female ratio was 1.0. Physical examination was done in 325 patients. Chest-wall pain was the most common diagnosis (in 28% of cases). Other causes included pulmonary (in 19%), minor traumatic (in 15%), idiopathic (in 12%) and psychogenic (in 5%); miscellaneous causes (in 21%) most often indicated pain referred from the upper respiratory tract and the abdomen. The most common physical finding was chest tenderness (in 41% of cases). Investigations included chest radiography (in 50% of cases), electrocardiography (in 18%) and determination of the hemoglobin concentration and of the leukocyte count (in 13%); the results were rarely positive. Only eight patients (2%) required admission to hospital, and there were no cases of myocardial ischemia. The findings suggest that health care costs may be reduced by more judicious use of investigations. We conclude that chest pain is an uncommon and usually benign complaint in the pediatric emergency department. Most causes are evident on careful physical examination.

Influenza in children with cancer.

We prospectively followed a group of unimmunized, immunosuppressed children with cancer to determine their relative risk of influenza and the severity of infection compared with those of siblings or matched community controls. The incidence of influenza infection was higher in children with cancer (23/73, 32%) than in control subjects (10/70, 14%, p = 0.02). A preseason hemagglutination inhibition titer greater than or equal to 1:32, generally used as a marker of successful immunization in vaccine trials, was protective for all children in the control groups, but did not prevent influenza infection in 24% of the patients with cancer. Infection rates of patients and community controls with titers greater than or equal to 1:32 differed significantly (p = 0.006). No significant differences were noted in duration of reported symptoms between groups, and clinical complications occurred too infrequently to analyze. However, 2 (11%) of 18 of the cancer patients with positive culture results were hospitalized during the illness and one patient developed a nosocomial infection. None of the control children was hospitalized. These findings suggest the need for further study of the immunologic response of immunosuppressed children to influenza infection and a clinical efficacy trial of the influenza vaccine in these patients.

Neonatal neurological status in a low-risk population after prenatal exposure to cigarettes, marijuana, and alcohol.

The neurological status of 9- and 30-day-old infants, as assessed by the Prechtl neurological examination, was significantly and differentially related to prenatal exposure of cigarettes, marijuana, and alcohol. Data on approximately 250 babies, born to healthy, white, predominantly middle-class women, were analyzed using discriminant function analyses controlling for potentially confounding variables. Prenatal cigarette exposure was associated with hypertonicity and increased nervous system excitation, particularly at 30 days, prenatal marijuana exposure was associated with symptoms similar to mild narcotic withdrawal, and prenatal exposure to relatively low levels of alcohol was associated with slightly lowered nervous system arousal at 9 days of age. The results were related to behavioral observations on neonates exposed to drugs prenatally.

Mortality among Canadian military personnel exposed to low-dose radiation.

We carried out a cohort study of mortality among 954 Canadian military personnel exposed to low-dose ionizing radiation during nuclear reactor clean-up operations at Chalk River Nuclear Laboratories, Chalk River, Ont., and during observation of atomic test blasts in the United States and Australia in the 1950s. Two controls matched for age, service, rank and trade were selected for each exposed subject. Mortality among the exposed and control groups was ascertained by means of record linkage with the Canadian Mortality Data Base. Survival analysis with life-table techniques did not reveal any difference in overall mortality between the exposed and control groups. Analysis of cause-specific mortality showed similar mortality patterns in the two groups; there was no elevation in the exposed group in the frequency of death from leukemia or thyroid cancer, the causes of death most often associated with radiation exposure. Analysis of survival by recorded gamma radiation dose also did not show any effect of radiation dose on mortality. The findings are in agreement with the current scientific literature on the risk of death from exposure to low-dose radiation.