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Biomedical subjects

N MacDonald

Publications and source records attributed to N MacDonald.

At least 37 records · Page 2Linked to original sources
PubMed1999

Screening for ovarian cancer: a pilot randomised controlled trial.

BACKGROUND: The value of screening for ovarian cancer is uncertain. We did a pilot randomised trial to assess multimodal screening with sequential CA 125 antigen and ultrasonography. METHODS: Postmenopausal women aged 45 years or older were randomised to a control group (n=10,977) or screened group (n=10,958). Women randomised to screening were offered three annual screens that involved measurement of serum CA 125, pelvic ultrasonography if CA 125 was 30 U/mL or more, and referral for gynaecological opinion if ovarian volume was 8.8 mL or more on ultrasonography. All women were followed up to see whether they developed invasive epithelial cancers of the ovary or fallopian tube (index cancers). FINDINGS: Of 468 women in the screened group with a raised CA 125, 29 were referred for a gynaecological opinion; screening detected an index cancer in six and 23 had false-positive screening results. The positive predictive value was 20.7%. During 7-year follow-up, ten further women with index cancers were identified in the screened group and 20 in the control group. Median survival of women with index cancers in the screened group was 72.9 months and in the control group was 41.8 months (p=0.0112). The number of deaths from an index cancer did not differ significantly between the control and screened groups (18 of 10,977 vs nine of 10,958, relative risk 2.0 [95% CI 0.78-5.13]). INTERPRETATION: These results show that a multimodal approach to ovarian cancer screening in a randomised trial is feasible and justify a larger randomised trial to see whether screening affects mortality.

CA-125 Antigen↗
PubMed1999

Increased mortality in postmenopausal women with serum CA125 elevation.

OBJECTIVES: Serum CA125 is used in monitoring treatment and detecting recurrence in ovarian cancer (OC). We have also shown that CA125 can be used with ultrasound for the early detection of OC. However, physiological, benign, and malignant conditions are also associated with CA125 elevation. The aim of the study was to determine the prognostic implications of CA125 elevation in asymptomatic postmenopausal women. METHODS: The study involved 771 volunteers in an OC screening trial of 22,000 women who had elevated serum CA125 levels (>/=30 U/ml). The control group consisted of an equal number of volunteers with normal levels. Survival was analyzed from the first point of CA125 elevation. Univariate analyses utilized the log-rank chi2 test. A logistic model was constructed for the multivariate analyses. RESULTS: The mean duration of follow-up was 1614 days (SD 897 days). Eighty-four women died (elevated CA125 group-62, control group-22). Univariate analyses showed that mortality in the elevated CA125 group was significantly greater (log-rank chi2 = 23.556, P < 0.0001, RR = 2.76), even when preexisting morbid conditions were excluded (log-rank chi2 = 14.644, P = 0.0001, RR = 2.4). Multivariate analysis showed that CA125 elevation, age (>60 years), and a prior history of cancer were associated with a poor prognosis. CONCLUSIONS: Serum CA125 elevation is associated with a significantly increased risk of death from all causes in the next 5 years. These findings may have implications for asymptomatic postmenopausal women with CA125 elevation.

CA-125 Antigen↗
PubMed1999

A comparison of national cancer registry and direct follow-up in the ascertainment of ovarian cancer.

The National Health Service Central Register (NHSCR) and direct follow-up were used to document ovarian and fallopian tube cancers in 22000 women from 1986 to 1993. Direct follow-up identified 47/49 cases (96%) and the NHSCR 38/49 (78%). NHSCR ascertainment was incomplete and direct follow-up provided additional information. These findings have implications for interpretation of national cancer statistics and for use of the NHSCR in research trials.

Cohort Studies↗
PubMed1999

Epidemiological features of pertussis in hospitalized patients in Canada, 1991-1997: report of the Immunization Monitoring Program--Active (IMPACT).

To assess the morbidity associated with the continued high levels of pertussis, we studied all children <2 years of age who were admitted to the 11 Immunization Monitoring Program--Active (IMPACT) centers, which constitute 85% of Canada's tertiary care pediatric beds. In the 7 years preceding implementation of acellular pertussis vaccine, a total of 1,082 pertussis cases were reported, of which 49.1% were culture-confirmed. The median age of the patients was 12.4 weeks; 78.9% of cases were in children <6 months of age. Complications of pertussis were common: pneumonia was reported in 9.4% of cases, new seizures in 2.3%, and encephalopathy in 0.5%. There were 10 deaths (0.9%), all in children < or =6 months of age. Duration of hospitalization was longer (9.3 days vs. 4.9 days; P = .001) and intensive care was required more frequently (19.2% vs. 4.9%; P = .001) in infants under <6 months of age than in those > or =6 months. Pertussis continues to cause significant morbidity and occasional mortality in Canada, particularly in young infants.

Canada↗
PubMed1999

Cost of chickenpox in Canada: part I. Cost of uncomplicated cases.

OBJECTIVE: The purpose of this study was to assess the direct medical costs and productivity losses associated with uncomplicated chickenpox (no hospitalization) in Canada. METHODS: A total of 179 otherwise healthy 1- to 9-year-old children with active chickenpox were recruited from schools, day care centers, and physician offices in 5 provinces. Direct medical (physician contacts, medication, and diagnostic tests) and nonmedical (personal expenses including child care) resources expended during the illness were determined by caregiver interview. Productivity losses attributable to the disease were determined by assessing caregiver time lost from work and daily activities. Unit costs for all resources were obtained from sources in 2 provinces, and per-patient treatment costs were determined from the patient, Ministry of Health, and societal perspectives. RESULTS: From a societal perspective, the per-case cost for children from 1 to 4 years of age and from 5 to 9 years of age was $370.2 and $236.5, respectively. Direct medical costs accounted for 10% of the total costs in both groups. The largest cost driver in patient care was caregiver productivity losses, which amounted to $316.5 in the younger age group and to $182.7 in the older age group. Based on an estimated yearly incidence of 344 656 cases of uncomplicated chickenpox in Canada, the total annual societal burden of the disease can be estimated at $109.2 million, with a cost to the Ministry of Health of $11.2 million. CONCLUSION: Chickenpox is one of the last common childhood diseases prevalent in Canada, and the uncomplicated disease, despite its rather benign course, imparts a large annual economic burden.

Canada↗
PubMed1999

Alopecia areata: identification and current treatment approaches.

Alopecia areata is a disease which occurs in 1.7% of the population (Safavi et al., 1995), often with devastating effects to patients and their families. In the past, this condition has been misunderstood and treated inadequately. New treatment modalities and support systems are offering hope to patients with alopecia areata.

Algorithms↗
PubMed1998

Bioethics for clinicians: 15. Quality end-of-life care.

A physician who receives a call from the emergency department to see a patient with heart failure will have a clear framework within which to approach this problem. The thesis of this article is that physicians do not have an analogous conceptual framework for approaching end-of-life care. The authors present and describe a framework for end-of-life care with 3 main elements: control of pain and other symptoms, the use of life-sustaining treatments and support of those who are dying and their families. This 3-part framework can be used by clinicians at the bedside to focus their effort in improving the quality of end-of-life care.

Advance Care Planning↗
PubMed1998

A march of folly.

Explore the source record for details and available documents.

Biomedical Research↗
PubMed1998

Palliative care--an essential component of cancer control.

Unlike in other nations, in Canada palliative care has its origins in university hospitals. It has subsequently developed in a few Canadian schools as an academic discipline closely linked with oncology programs. Although this model is successful, other faculties of medicine and cancer centres have been slow to emulate it. Today, the situation is rapidly changing, and both palliative care and oncology professionals are re-examining the manifest need for collaborative efforts in patient care, research and education. Palliative care must be regarded as an essential component of cancer care, its principles must be applied throughout the course of the illness and, as in other phases of cancer control, palliative care should be regarded as an exercise in prevention--prevention of suffering. This article discusses practical applications that flow from acceptance of these concepts.

Canada↗
PubMed1998

Acute-phase neurologic complications of Haemophilus influenzae type b meningitis: association with developmental problems at school age.

The purposes of this study were to describe the incidence of acute-phase neurologic complications in a sample of 126 children with Haemophilus influenzae type b meningitis, and to determine if these complications were associated with higher rates of learning and behavior problems at school age. Risks were assessed by comparing rates of adverse psychoeducational outcomes in the 53 children in the sample with complications to corresponding outcome rates in the 67 children who were free of neurologic complications and who did not have abnormal electroencephalograms (EEGs) or computed tomographic (CT) scans. Comparisons were made by means of logistic regression analysis. Twenty-nine children (23% of the sample) had seizures, 16 (13%) were comatose or obtunded, 15 (12%) had sensorineural hearing loss, 8 (6%) had hemiparesis, and 7 (6%) had cranial nerve deficits other than hearing loss. Relative to children without complications, those with complications had higher rates of grade repetition and substandard performance on neuropsychological and achievement testing. Adverse outcomes, however, consisted primarily of more subtle cognitive and learning problems; only two of the children in the sample obtained prorated IQ scores below 70. Sequelae were associated with persistent neurologic deficits and bilateral hearing loss, as well as with transient symptoms including seizures, coma, and hemiparesis. While study findings argue against adverse consequences for the vast majority of children treated for this disease, the results clarify learning and behavior outcomes and indicate which children are at greatest risk.

Adolescent↗
PubMed1997

A Canadian survey of issues in cancer pain management.

We report the analysis of a cancer management survey mailed to a representative group of health professionals in 1994. The goals of the study were to gather information on cancer pain treatment practices, and to obtain health professional views on obstacles to ideal pain management. The survey, designed by a working party of pharmacists, nurses and physicians, was distributed to 14,628 physicians. A total of 2,686 physicians responded to the survey, including 39% of medical or radiation oncologists, and 18.19% of physicians who listed their primary interest as Family Medicine. Reflecting the modest emphasis placed on palliative care and cancer pain management in the current Canadian milieu, 67% of physicians rated their past teaching experience as only "fair" or "poor." Lack of exposure to pain education was reflected in the response to a series of hypothetical case scenarios exploring physician choices in managing severe cancer pain. For example, in the initial management of a cancer patient with severe pain, 50% of physicians would not use a strong opioid in the absence of other contraindications to opioid use. A wide variety of analgesics and non-pharmacologic techniques is available to Canadian physicians to assist patients with pain. Few physicians identified the unavailability of analgesics or analgesic techniques as limiting factors in pain management. We conclude that greater emphasis should be placed on pain education in our training programmes. We suggest that further surveys of this type, sponsored by our provincial colleges and medical organizations, can provide feedback which will enhance the adherence by Canadian physicians to published guidelines for pain management.

Canada↗
PubMed1997

Does ribavirin impact on the hospital course of children with respiratory syncytial virus (RSV) infection? An analysis using the pediatric investigators collaborative network on infections in Canada (PICNIC) RSV database.

OBJECTIVES: To determine the relationship between receipt of aerosolized ribavirin and the hospital course of high-risk infants and children with respiratory syncytial virus (RSV) lower respiratory infection (LRI). METHODS: The 1993-1994 Pediatric Investigators Collaborative Network on Infections in Canada (PICNIC) RSV database consists of prospectively enrolled children with acute RSV LRI, admitted to nine Canadian pediatric tertiary care centers. After excluding cases with compromised immunity and/or nosocomial infection, subsets with any congenital heart disease (CHD), chronic lung disease (CLD), age </=6 weeks (INFANT), gestation </=36 weeks (PREM), or severe disease within 48 hours of admission as shown by an oxygen saturation </=90% or an FiO2 requirement of >.35 (EARLY HYPOXIA) were studied in two ways. First, each risk group subset was analyzed separately to assess the association between ribavirin receipt and measures of disease severity including duration of intensive care, mechanical ventilation, hypoxia and RSV-attributable hospital stay. Secondly, ribavirin was added as an independent variable to a previously described multiple regression model for RSV-attributable length of hospital stay and two mutually exclusive subsets were analyzed: 1) previously healthy patients with >/=1 of: INFANT, PREM, or EARLY HYPOXIA; 2) patients with CHD and/or CLD. RESULTS: Between January 1993 and June 1994, 1425 community-acquired hospitalized cases of RSV LRI were entered into the RSV database. Among these 750 (52.6%) fit into one or more of the defined subsets including 97 CHD, 134 CLD, 213 INFANT, 211 PREM, and 463 EARLY HYPOXIA. The proportion ventilated in each group was 20.6%, 20.9%, 15.5%, 15.2%, and 13.3%, respectively. Across the subsets ribavirin use ranged from 36% to 57% of ventilated patients and 6% to 39% of nonventilated patients. For nonventilated patients in each subset the median RSV-attributable hospital length of stay (RSV-LOS) was 2 to 3 days longer for ribavirin recipients and the duration of hypoxia was significantly increased. Duration of intensive care unit (ICU) stay was also increased for all ribavirin-treated subgroups except those with CHD. In contrast, for ventilated patients, ribavirin therapy was not significantly associated with any of the outcome measures regardless of risk group. In the multiple regression model, ribavirin was significantly associated with a prolonged RSV-LOS both for children with CHD and/or CLD as well as for those whose only risk factors included INFANT, PREM, and/or EARLY HYPOXIA. CONCLUSIONS: These data raise further doubts about the clinical effectiveness of ribavirin in infants and children with risk factors for severe disease. Selection bias, with ribavirin used for sicker children, may have influenced outcome. Nevertheless the long durations of hospitalization, ICU, ventilation, and oxygen supplementation in nonventilated ribavirin recipients stress the need for further randomized trials to assess its efficacy.

Antiviral Agents↗