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Biomedical subjects

A M O'Connor

Publications and source records attributed to A M O'Connor.

At least 19 recordsLinked to original sources
PubMed1999

Changes in Canadian women's mammography rates since the implementation of mass screening programs.

OBJECTIVES: This study reports on Canadian mammography rates between 1990, when mass screening programs were launched, and 1994/95. METHODS: Mammography rates from 2 national surveys were compared according to the presence of a provincial screening program. RESULTS: Mammography rates among women aged 50 to 69 years (the targeted group) increased significantly, by 16%; increases were twice as high in provinces with screening programs. Among women in their 40s (nontargeted group), the changes were insignificant and independent of screening program status. CONCLUSIONS: Screening programs appear to have influenced the mammography rates of targeted women aged 50 to 69 years.

Adult↗
PubMed1998

A decision aid for women considering hormone therapy after menopause: decision support framework and evaluation.

Although postmenopausal women are advised to consider their values when deliberating about potential benefits and risks of hormone therapy (HRT), feasible, effective methods of decision support in primary care have yet to be established. Using an explicit decision support framework, we developed a self-administered HRT decision aid and evaluated it in a before/after study of 94 women from six family practices. An audiotape guided women through an illustrated booklet including: detailed information about HRT benefits and risks tailored to a woman's clinical risk, and a values clarification exercise to promote informed decision making consistent with personal values. After using the decision aid participants: had better general knowledge and more realistic personal expectations of HRT benefits and risks; and, felt more certain, informed, clear about values, and supported in decision making. Women's values elicited in the clarification exercise were 84% accurate in discriminating between decisions. Women with polarized preferences at baseline did not change their minds, but were better informed. Changes in preferences occurred in the uncertain group, with equal numbers accepting or declining HRT. Most participants found the decision aid comprehensible, acceptable in length and pace, and balanced. Decision aids are useful in preparing women for decision making about this complex, personal issue.

Aged↗
PubMed1998

Emergency physicians' attitudes toward and use of clinical decision rules for radiography.

OBJECTIVES: 1) To assess Canadian emergency physicians' (EPs') use of and attitudes toward 2 radiographic clinical decision rules that have recently been developed and to identify physician characteristics associated with decision rule use; 2) to determine the use of CT head and cervical spine radiography by EPs and their beliefs about the appropriateness of expert recommendations supporting the routine use of these radiographic procedures; and 3) to determine the potential acceptance of clinical decision rules for CT scan in patients with minor head injury and cervical spine radiography in trauma patients. METHODS: A cross-sectional anonymous mail survey of a random sample of 300 members of the Canadian Association of Emergency Physicians using Dillman's Total Design Method for mail surveys. RESULTS: Of 288 eligible physicians, 232 (81%) responded. More than 95% of the respondents stated they currently used the Ottawa Ankle Rules and were willing to consider using the newly developed Ottawa Knee Rule. Physician characteristics related to frequent use of the Ottawa Ankle Rules were younger age, fewer years since graduating from medical school, part time or resident employment status, working in a hospital without a CT scanner, and believing that decision rules are not oversimplified cookbook medicine or too rigid to apply. Eighty-five percent did not agree that all patients with minor head injuries should receive a CT head scan and only 3.5% stated they always refer such patients for CT scan. Similarly, 78.5% of the respondents did not agree that all trauma patients should receive cervical spine radiography and only 13.2% said they always refer such patients for cervical spine radiography. Ninety-seven and 98% stated they would be willing to consider using well-validated decision rules for CT scan of the head and cervical spine radiography, respectively. Fifty-two percent and 67% of the respondents required the proposed CT and C-spine to be 100% sensitive for identifying serious injuries, respectively. CONCLUSIONS: Canadian EPs are generally supportive of clinical decision rules and, in particular, have very positive attitudes toward the Ottawa Ankle and Knee Rules. Furthermore, EPs disagree with recommendations for routine use of CT head and cervical spine radiography and strongly support the development of well-validated decision rules for the use of CT head and cervical spine radiography. Most EPs expected the latter rules to be 100% sensitive for acute clinically significant lesions.

Adult↗
PubMed1998

Can postal prompts from general practitioners improve the uptake of breast screening? A randomised controlled trial in one east London general practice.

OBJECTIVE: To determine the effect on the uptake of breast screening of a personalized letter from the general practitioner recommending mammography, sent to coincide with an invitation from the NHS breast screening programme. DESIGN: Randomised control trial with stratification of prognostic variables. SETTING: A group practice in Hackney, east London. SUBJECTS: 473 women invited for breast screening by the City and East London Breast Screening Service. OUTCOME MEASURE: Attendance for mammography. RESULTS: All women in the randomised trial were followed up; 134 of 236 (57%) randomly allocated to receive the prompting letter attended for mammography compared with 120 of 234 (51%) controls This difference was not significant (chi 2 = 1.43, p = 0.23) CONCLUSION: Personal recommendation by a letter prompting attendance for mammography from the general practitioner known best to women due to be screened did not improve uptake of breast screening in this east London practice. Other strategies are needed to increase uptake of mammography in inner cities.

Family Practice↗
PubMed1997

Deciding about mechanical ventilation in end-stage chronic obstructive pulmonary disease: how respirologists perceive their role.

OBJECTIVE: To determine when respirologists approach patients with end-stage chronic obstructive pulmonary disease (COPD) to decide about the use of mechanical ventilation, what information they provide to patients and how they provide it. DESIGN: Self-administered national survey. PARTICIPANTS: All Canadian specialists in respiratory medicine; of 401 eligible respirologists, 279 (69.6%) returned a completed questionnaire. OUTCOME MEASURES: Timing and content of doctor-patient discussions regarding mechanical ventilation; physicians' perception of their level of involvement in the decision-making process; and patient and physician characteristics that may influence decisions. RESULTS: Discussions were reported to occur most often at advanced stages of COPD: when the patient's dyspnea was severe (reported by 235 [84.2%] of the respondents) or when the patient's forced expiratory volume in the first second was 30% or less than predicted value (reported by 210 [75.3%]). A total of 120 respondents (43.0%) stated that they discuss mechanical ventilation with 40% or less of their COPD patients before an exacerbation necessitates ventilatory support. Most (154 [55.2%]) described the decision-making process as a collaboration between patient and physician; 83 (29.7%) reported that the patient decides after he or she has considered the physician's opinion. Over half (148 [53.0%]) of the respondents indicated that they occasionally, often or always modify the information provided to patients in order to influence their decision about mechanical ventilation. CONCLUSIONS: Discussions with COPD patients concerning end-of-life decisions about mechanical ventilation are reported to occur in advanced stages of the disease or not at all, with patients' input where possible. Information presented to patients is often modified in order to influence the decision. Future studies should explore ways to involve patients further in the decision-making process and to improve the process for both patients and physicians.

Adult↗
PubMed1997

Physicians' opinions about decision aids for patients considering systemic adjuvant therapy for axillary-node negative breast cancer.

PURPOSE: To examine variations in physicians' opinions about the appropriateness and content of decision aids for women with breast cancer and criteria for their evaluation. METHODS: Cross-sectional survey of all 144 Ontario oncologists by Dillman's mailed survey design. The response rate was 87%. RESULTS: The predominant current practice pattern was to spontaneously inform patients about the treatment recommendations, degree of certainty regarding the recommendations, treatment regime, benefits and side effects. Most respondents (94%) endorsed patient decision aids, particularly when there was high uncertainty about providing adjuvant treatment. Over three-quarters endorsed measuring the following outcomes of decision aids: patients' clarity of trade-offs involved (e.g. survival vs. side effects); comprehension of treatment alternatives, risks and benefits; accuracy of expectations; decision satisfaction; anxiety; commitment to the decision; length of time to complete the decision aid; and decision uncertainty. The least support was for the use of the decision itself as an outcome measure. CONCLUSIONS: There is considerable consensus regarding the indications for, content and criteria for evaluating decision aids which should be considered when developing aids relevant to the needs of clinicians and patients.

Adult↗
PubMed1997

Characteristics of clients with schizophrenia who express certainty or uncertainty about continuing treatment with depot neuroleptic medication.

In this exploratory study, the factors corresponding to clients' certainty or uncertainty in continuing with depot neuroleptic medication for schizophrenia were examined. Ninety-four participants from a tertiary care schizophrenia clinic received an educational intervention aid containing information about treatment risks and benefits and were interviewed to elicit their levels of decisional conflict, self-efficacy, and emotional support, as well as expectations of risks and benefits of treatment. Eighty-seven percent of participants decided to continue treatment. Clients who expressed uncertainty (10%) about continuing with treatment had higher levels of decisional conflict (p = .000), lower levels of decision self-efficacy (p = .037) and decision emotional control (p = .003), lower expectations of hospitalization if treatment was stopped (p = .04) as well as lower expectations of benefits and higher expectations of side effects (p = .04), if treatment continued. In addition, reasons identified by participants for certainty or uncertainty were reported. The research may be useful in increasing the awareness of clinicians about the factors contributing to treatment decision making by clients diagnosed with schizophrenia and ultimately improve collaborative decision making.

Adult↗
PubMed1996

Framing effects on expectations, decisions, and side effects experienced: the case of influenza immunization.

OBJECTIVE: To examine the effects of using positive or negative frames to describe influenza vaccine benefits and side effects on patients' expectations, decisions, decisional conflict, and reported side effects. METHODS: 292 previously unimmunized patients with chronic respiratory or cardiac disease were randomly assigned to receive benefit/risk information that was framed: (1) positively as the percentage who remain free of influenza and have no vaccine side effects, or (2) negatively as the percentage who acquire influenza and have vaccine side effects. Questionnaires elicited expectations, decisions, and decisional conflict. Vaccines were telephoned 3 days later for a self-report of local and systemic side effects and work absenteeism. RESULTS: Both groups had similar immunization rates and decisional conflict scores. The positive frame group had lower and more realistic expectations of vaccine side effects, fewer systemic side effects, and less work absenteeism (p < 0.05). CONCLUSION: In contrast to previous studies of health care workers, framing did not influence patients' decisions, possibly due to the patients' awareness of their higher risk of influenza complications and greater desire to follow recommendations. The common practice of using negative frames when describing probabilities of side effects may need to be reexamined, considering its deleterious influence on self-reported side effects and work absenteeism.

Aged↗
PubMed1996

What do physicians tell patients with end-stage COPD about intubation and mechanical ventilation?

BACKGROUND: At some point in time, many patients with end-stage COPD require intubation and mechanical ventilation (MV) to sustain life. MV decisions are most effective when the patient and physician have discussed the options in advance. The purpose of this study was to examine how the physician perceives the decision-making process. METHODS: Fifteen respirologists were interviewed to elicit information regarding intubation and MV, and the exchange of information between patients and physicians. Emergent themes were coded using a qualitative approach and were verified by a blinded researcher. RESULTS: Respondents included ten academic and five community-based respirologists from seven hospitals. Most physicians were men with between 4 and 37 years experience. Narratives were very similar in content and seemed well rehearsed. Approach and delivery, however, were unique to each physician. Fourteen respirologists emphasized the importance of knowing patients as individuals prior to initiating this discussion. This period of familiarization often dictated when the physician believed the ventilation discussion is appropriate. Individual physician comfort also appeared to affect the timing of the discussion. Physicians discussed the many elements that make the MV discussion difficult for physicians and patients. Intubation details included a tube being placed down the throat, the discomfort associated with the tube, the inability to speak, and the availability of pain reducing medication. All physicians discussed the possibility of death with their patients, although many preferred euphemisms in initial discussions. All physicians indicated that intubation is presented as the patient's choice. However, all but one physician commonly framed their discussions in order to influence patient choice. The positive or negative framing seemed contingent on the physician's expectations for that patient. CONCLUSIONS: Our interviews demonstrated considerable agreement between physicians about the content and timing of the intubation MV discussion. Physicians all agreed that knowing the patient and his or her situation was important in determining the timing of the intubation and MV discussion. Practice style and individual physician comfort with end-of-life decisions may influence the timing of the discussion and possibly the number of patients who are finally approached. All physicians advocated a shared decision-making approach, but they strongly influence the deliberation process. Thus, the decision-making model seemed to be physician driven in this study.

Attitude of Health Personnel↗
PubMed1995

Brain glucose uptake and unawareness of hypoglycemia in patients with insulin-dependent diabetes mellitus.

BACKGROUND: In patients with insulin-dependent diabetes mellitus (IDDM) whose treatment results in nearly normal mean plasma glucose concentrations, an unawareness of hypoglycemia can develop, and such patients are at increased risk for seizures and coma. We tested the hypothesis that during hypoglycemia, these patients would have normal glucose uptake in the brain and that consequently no sympathoadrenal activation would begin, resulting in an unawareness of hypoglycemia. METHODS: We measured glucose uptake in the brain at plasma glucose concentrations of 105 and 54 mg per deciliter (5.8 and 3.0 mmol per liter) in 24 patients with IDDM, stratified into three groups according to their glycosylated hemoglobin values (mean [+/- SD] values, 7.2 +/- 0.5, 8.5 +/- 0.4, and 10.2 +/- 1.3 percent) and compared the values for brain glucose uptake with those measured in 15 normal subjects at plasma glucose concentrations of 85 and 55 mg per deciliter (4.2 and 3.1 mmol per liter). We also recorded the subjects' hypoglycemic-symptom scores and measured their plasma concentrations of counterregulatory hormones. RESULTS: There was no significant change in the uptake of glucose in the brain (calculated as the uptake during hypoglycemia minus the uptake during normoglycemia) among the patients with IDDM who had the lowest glycosylated hemoglobin values (+0.6 +/- 2.0 mg [3.3 +/- 11.1 mumol] per 100 g of brain tissue per minute, P = 0.39). Conversely, glucose uptake in the brain fell in both the group with intermediate values (a decrease of 1.3 +/- 1.0 mg [7.2 +/- 5.6 mumol] per 100 g per minute, P = 0.009) and the group with the highest values (a decrease of 1.8 +/- 1.6 mg [10.0 +/- 9.0 mumol] per 100 g per minute, P = 0.01), as it did in the normal subjects (a decrease of 1.6 +/- 1.8 mg [9.0 +/- 10.1 mumol] per 100 g per minute, P = 0.003). The responses of plasma epinephrine and pancreatic polypeptide and the frequency of symptoms of hypoglycemia were lowest in the group with the lowest glycosylated hemoglobin values. CONCLUSIONS: During hypoglycemia, patients with IDDM who have nearly normal glycosylated hemoglobin values have normal glucose uptake in the brain, which preserves cerebral metabolism, reduces the responses of counterregulatory hormones, and causes an unawareness of hypoglycemia.

Adult↗
PubMed1995

Speech and language disorders in patients with high grade glioma and its influence on prognosis.

One hundred and sixteen patients with high grade glioma were entered into a prospective phase two study and treated with accelerated radiotherapy from 1988 to 1993. In this cohort of patients we analysed speech deficit as a subdivision of global functional status in terms of incidence, category and prognosis for survival. Forty three patients (37%) had a speech deficit at presentation. Eighty percent of these had a component of expressive dysphasia, associated with considerable degree of awareness and distress. The overall median survival was 9.5 months. On univariate analysis, median survival in patients with speech difficulties (6 months) was worse than patients with normal speech (10.5 months) (log rang p = 0.005). Multivariate analysis established independent significance from age, Karnofsky Performance Status (KPS), gender, histological grade, extent of surgery and seizures. This paper highlights the importance of assessing individual categories of functional disability which in patients with high grade glioma include mobility, cognitive function and communication. Each of these factors may seriously affect an individual's activities of daily living, hence quality of life and separate analysis has a number of clinical implications. Firstly, with over a third of patients suffering speech difficulties, adequate speech therapy facilities should be freely available to score the degree of deficit, devise coping strategies and institute communication therapy. Secondly, an understanding of prognostic factors aids the critical analysis of phase two studies and the design and stratification of future prospective trials which should include an analysis of speech deficit. Thirdly, separating individual patients into good and bad prognostic groups can assist strategic management decisions.

Adult↗
PubMed1995

Reliability and validity of measures used to elicit health expectations, values, tradeoffs and intentions to be immunized for hepatitis B.

We evaluated measures eliciting health expectations, health values, health tradeoffs and intentions to take hepatitis B (HepB) vaccine among health science and technology students. We tested 23 students two weeks apart and then surveyed a cross-section of 373 students in 6 health disciplines. In a subsequent prospective study, 863 students were tested, invited to be immunized, and followed to observe who presented for immunization. The test-retest reliability coefficients exceeded 0.80 for all but the health value measures. All but the health values measures discriminated between those with strong and weak intentions to be immunized. Expectation measures discriminated among disciplines with different risks of exposure to blood and body fluids. The intention, health tradeoff and expectation measures discriminated between those who did and did not present themselves for immunization. We conclude that all but the health values measures met acceptable standards of reliability and validity. Health value tradeoff measures are more discriminating than health value measures.

Allied Health Personnel↗
PubMed1995

Human gastrin and vasoactive intestinal polypeptide responses to endurance running in relation to training status and fluid ingested.

1. Plasma concentrations of gastrin, glucose, vasoactive intestinal polypeptide and non-esterified fatty acid were analysed in six male endurance runners and six male hockey players before, during and 15 min after 90 min treadmill running at 65% maximum oxygen uptake under two conditions: no fluid ingestion (trial A) and ingestion of 8% maltodextrin solution (trial B). 2. Exercise resulted in significantly elevated plasma gastrin concentrations compared with resting values in both groups after trial A (endurance runners, 69.4 ng/l; hockey players 71.4 ng/l) and trial B (endurance runners, 105.5 ng/l; hockey players, 83.2 ng/l). The gastrin response was not significantly different between the trials. 3. Plasma vasoactive intestinal polypeptide levels increased significantly beyond resting levels for both groups during trial A (endurance runners, 76.1 +/- 53.7 ng/l; hockey players 155.6 +/- 41.9 ng/l) and trial B (endurance runners 47.5 +/- 21.3 ng/l; hockey players 132.9 +/- 43.9 ng/l). The vasoactive intestinal polypeptide response to trial B was significantly attenuated compared with trial A. 4. There were no significant differences between endurance runners and hockey players for plasma gastrin, although hockey players produced significantly elevated concentrations of plasma vasoactive intestinal polypeptide after both trials compared with endurance runners. 5. Plasma glucose levels throughout trial B were significantly greater than after trial A irrespective of the group. Plasma glucose concentrations were not significantly different between endurance runners and hockey players. 6. Plasma non-esterified fatty acid concentrations rose significantly for both groups throughout exercise. Trial B resulted in an attenuated non-esterified fatty acid response compared with trial A.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Circulating gastrointestinal hormone changes in marathon running.

The purpose of this study was to observe the effect of marathon running on the release of gastrointestinal hormones and whether these might be related to gastrointestinal disturbances in marathon runners. Vasoactive intestinal polypeptide, gastrin, secretin, pancreatic polypeptide, neurokinin A, pancreastatin, insulin and glucagon-like peptide 1 were measured before, immediately upon finishing and 30 min after the race. Twenty-six competitors of the 1992 Belfast Marathon volunteered for this study. They had a mean age of 37 years and a mean finishing time of 239 min. Eight of the subjects complained of gastrointestinal distress during the race. The circulating concentration of all the GI hormones measured, except insulin were significantly elevated after the race. There was no significant change in glucose levels at the finish of the race. Statistical analysis revealed no direct relationship between the large increases in hormone levels and the occurrence of GI symptoms. These results show that GI hormone concentrations are affected by marathon running. Mechanisms of release and possible roles are discussed.

Adult↗