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Biomedical subjects

S Lewis

Publications and source records attributed to S Lewis.

At least 235 records · Page 13Linked to original sources
PubMed1995

Paradox, process and perception: the role of organizations in clinical practice guidelines development.

The role of organizations in the development of clinical practice guidelines (CPGs) has received virtually no analytic attention. In a strictly rational and disinterested world, CPGs would be assessed on the basis of the supporting evidence and applicability to practice. However, factors that have more to do with medical sociology play a key role in CPG acceptance and, in some cases, development. The entire concept of CPGs entails troubling paradoxes, many of which turn on the distinction between scientific evidence and the sociologic determinants of validation and implementation. At the root of the question of organizational roles is the issue of values: Whose values should be at the table? What values are legitimate? From what perspectives should the utility of a procedure or technology be addressed? The Canadian health care system is a largely public creature, and CPG development is part of the public policy process. In this context, decisions about organizational roles must be sensitive to conflict of interest and a diversity of values. A provisional model for participation in CPG processes would minimize the role of organizations per se, although individual participants would no doubt reflect the legitimate interests of their affiliations without representing them formally.

Canada↗
PubMed1995

Report on activities and attitudes of organizations active in the clinical practice guidelines field.

The organizing committee of a workshop on clinical practice guidelines (CPGs) surveyed invited organizations on their attitudes and activities related to five topics to be covered during the workshop sessions: organizational roles, priority setting, guidelines implementation, guidelines evaluation and development of a network of those active in the CPG field. Organizational roles: The national specialty societies were felt to have the largest role to play; the smallest roles were assigned to consumers, who were seen to have a role mainly in priority setting, and to industry and government, both of which were seen to have primarily a funding role. Many barriers to collaboration were identified, the solutions to all of which appeared to be better communication, establishment of common principles and clear role definitions. Priority setting: There was considerable agreement on the criteria that should be used to set priorities for CPG activities: the burden of disease on population health, the state of scientific knowledge, the cost of treatment and the economic burden of disease on society were seen as important factors, whereas the costs of guidelines development and practitioner interest in guidelines development were seen as less important. Organizations were unable to give much information on how they set priorities. Guidelines implementation: Most of the organizations surveyed did not actively try to ensure the implementation of guidelines, although a considerable minority devoted resources to implementation. The 38% of organizations that implemented guidelines actively listed a wide variety of activities, including training, use of local opinion leaders, information technology, local consensus processes and counter detailing. Guidelines evaluation: Formal evaluation of guidelines was undertaken by fewer than 13% of the responding organizations. All the evaluations incorporated assessments before and after guideline implementation, and some used primary patient data. Barriers to evaluation included lack of money, time, data or expertise. CPG Network: Most of the respondents felt that all organizations and individuals interested or involved in guidelines should form the membership of the network. The three most important functions of such a network were deemed to be (a) to facilitate collaboration among those involved in the CPG process, (b) to maintain an information centre on CPGs and (c) to provide expertise to the CPG process. It was felt that the network should have some formal structure and communicate through e-mail and print media.

Attitude↗
PubMed1995

Hematological features of patients with myelodysplastic syndromes associated with a chromosome 5q deletion.

The hematological and clinical features of 26 patients with myelodysplasia and a chromosome 5q deletion in the bone marrow are presented. We have examined the relationship of French-American-British Co-operative Group (FAB) 1982 classification and bone marrow karyotype at diagnosis with patient outcome and the presence or absence of the classical features of the 5q-syndrome. Those patients classified as refractory anemia (RA) with no additional karyotypic abnormalities have the typical features of the 5q-syndrome and a good prognosis. None of the patients in this group transformed to acute leukemia during the period of follow-up. Patients with either refractory anemia and excess blasts (RAEB) or additional karyotypic abnormalities show many of the hematologic features of the 5q-syndrome but do not share the good prognosis. We conclude that the 5q-syndrome may be best defined as primary MDS of the FAB type RA with a 5q deletion as the sole karyotypic abnormality. This simple definition will distinguish patients with a good prognosis and all the classical features of the 5q-syndrome.

Acute Disease↗
PubMed1995

A single center randomized trial assessing use of a vascular hemostasis device vs. conventional manual compression following PTCA: what are the potential resource savings?

We undertook a randomized controlled trial comparing VasoSeal, a collagen vascular hemostasis device (VHD), with manual compression to assess its role and potential cost savings in the PTCA population. Of 460 patients, 359 were excluded due to clinical instability (30%), groin problems (18%), suboptimal PTCA result (15%), and other reasons (37%). The remaining 101 patients were randomized to either VHD (51) or manual compression (50). Hemostasis time, time to ambulation, duration of hospital stay, and nursing time and intensity were significantly reduced in the VHD group. There were no major groin complications in either treatment arm but there was a trend toward more minor groin complications in the VHD patients. The application of VasoSeal reduced resource use in this randomized study and may translate into significant cost reductions in the general coronary angioplasty population.

Adult↗
PubMed1995

Organic and psychosocial risk factors for duodenal ulcer.

Duodenal ulcer (DU) is a common medical disorder which frequently becomes chronic. The factors involved in the aetiology of DU are poorly understood. Evidence for the contribution of psychosocial factors to the onset of DU is reviewed in the context of evidence of organic factors, genetic and environmental, with special reference to new evidence of infectious agents in the aetiology of DU. Recent progress in understanding of biological forces of duodenal ulcer disease has lead to a substantially revised view of psychosomatic factors. Although these may be of significance, their relative contribution to aetiology is likely to be modest.

Duodenal Ulcer↗
PubMed1995

Psychological morbidity in newly referred patients with cancer.

Over the last 10 yr, research has shown that although the majority of patients are able to cope with the stresses of cancer, a substantial number have difficulties which require some form of psychological help. This study reports on the levels of psychological distress in a heterogeneous group of 117 newly referred out-patients with cancer over a 6-month period. Each patient reported their levels of distress by completing two self-administered questionnaires (the GHQ-30 and HADS) on three separate occasions. A descriptive examination of the socio-demographic characteristics of the sample was also carried out. At the first assessment 30% of the sample scored above the threshold for probable psychiatric disorder on the GHQ-30 and 26% on the HADS anxiety scale. At 6 months follow-up levels had fallen to 21% for the GHQ-30 and 10% for HADS anxiety. The numbers of probable cases of HADS depression was 7% at the first assessment and 5% at follow-up. Differences in levels of psychological morbidity according to age, sex, partner status and socioeconomic group were demonstrated. However, we were unable to make any firm conclusions as to whether these effects were independent of each other as a controlled multivariate analysis of the data set was not possible.

Adaptation, Psychological↗
PubMed1995

Ethylene oxide: evaluation of genotoxicity data and an exploratory assessment of genetic risk.

A risk estimate of the heritable effects of ethylene oxide exposure, using the parallelogram approach, as suggested by Frits Sobels, is described. The approach is based on available data on the ethylene oxide-induced responses for the same genetic endpoint in somatic cells of both laboratory animals and humans, and for germ cell mutations in the same laboratory animal. Human germ cell effects are estimated. The available data sets for this approach were evaluated. We consider this as complementary to the genetic risk assessment carried out by U.S. EPA scientists, in which the risk from heritable (reciprocal) translocations induced by ethylene oxide was estimated. In the present study we restricted our assessment to dominant mutations. The sensitivity factor relating mouse to man was based on ethylene oxide-induced HPRT mutant frequencies in lymphocytes in vivo. From this comparison, it could be concluded that occupational exposure for 1 year to 1 ppm ethylene oxide would lead to a risk of a dominantly inherited disease in the offspring of 4 x 10(-4) above the background level. The uncertainty interval of this figure is quite large (0.6-28) x 10(-4). The values are compatible with the existing estimates of the corresponding risk from exposure to low LET radiation when the genotoxic potency ratio of ethylene oxide and radiation is considered. This risk estimation approach has allowed us to identify additional data that are required for a more complete risk estimation of the heritable effects of ethylene oxide, or indeed any mutagenic chemical.

Animals↗
PubMed1995

Powerlessness, health and mortality: a longitudinal study of older men and mature women.

National samples of older men (age 45-59 in 1966) and mature women (30-44 in 1967), surveyed periodically over more than a decade, establish the association over time between the sense of powerlessness and various indices of health status (chiefly, psychosocial symptoms and limits on physical activities). The results are basically coordinate for men and women, and they are replicated for initially healthy and initially impaired sub-samples. The results show that: (1) in each year, powerlessness is associated with greater activity limits and more psychosocial symptoms; (2) powerlessness also provides prospective prediction, since high initial powerlessness scores are associated with health problems observed five and ten years later, with initial health controlled; (3) increasing powerlessness accompanies deterioration in health (with stringent controls on prior health); and (4) for a sub-sample of men, mortality between 1976 and 1981 is also associated with initially high powerlessness scores (with prior health controlled). These results are discussed for their import in relation to the steadily growing interest in social psychological factors in health.

Adult↗
PubMed1995

Correlates of left-handedness in a large sample of schizophrenic patients.

Questionnaire data concerning hand preference from the parents of 686 schizophrenic patients were used to test predictions relevant to neurodevelopmental models of schizophrenia. In line with predictions, left-handed patients (n = 94) had a more frequent history of difficult birth, more childhood cognitive and behavioural abnormalities and more persistent auditory hallucinations than did right-handed patients.

Adolescent↗
PubMed1995

The influence of audiotapes on patient participation in the cancer consultation.

This study examined the effect of providing patients with an audiotape of a previous consultation on their level of participation during a subsequent consultation. 117 newly referred medical oncology patients randomised to receive a tape (n = 63) or not (n = 54) had two linked consultations which were both audiotaped. A content analysis revealed no significant differences between tape and control group in the mean number of questions asked during the second consultation. However, significantly more tape group patients (77%) asked for clarification of at least one piece of information compared to the control group (57%) (P = 0.04). A larger number of control group patients (61%) made at least one request for facts already provided in their first consultation compared to tape group patients (39%) (P = 0.05). Audiotapes appear to facilitate patients' requests for the clarification of previously given information and permit the re-absorption of complex information given when patients may have been too distressed for it to be assimilated.

Adult↗
PubMed1995

The efficacy of audiotapes in promoting psychological well-being in cancer patients: a randomised, controlled trial.

Open or uncontrolled studies have suggested that providing cancer patients with audiotapes of their clinical interviews can improve information recall and reduce psychological distress. We tested these hypotheses in a 'clinician-blind', prospective, randomised controlled trial. A total of 117 patients newly referred to a medical oncology clinic who were to be given 'bad news' had their consultations audiotaped. Blind to the clinician, patients were randomly allocated to receive a copy of the tape to play at home or not (control group). At 6 months follow-up, tape group patients reported positive attitudes to the audiotape and were shown to recall significantly more information about their illness than did controls. Overall improvement in psychological distress at 1 and 6 months follow-up, as measured with the 30-item General Health Questionnaire and the Hospital Anxiety and Depression Scale was no different in the two groups. However, a second-order interaction suggested that poor-prognosis patients were disadvantaged specifically by access to the audiotape, with less improvement in psychological distress at 6 months follow-up than non-tape controls. Patient access to audiotapes of clinical interviews promotes factual retention but does not reliably reduce psychological distress and may be actively unhelpful in some subgroups of patients.

Adult↗
PubMed1995

Effect of oral digoxin, topical ouabain and salbutamol on transepithelial nasal potential difference in patients with cystic fibrosis.

1. Airway epithelium in cystic fibrosis is characterized by a defect in chloride secretion across the apical membrane and an increase in sodium absorption. The increased rate of sodium absorption can be inhibited in vitro by ouabain, a Na(+)-K(+)-ATPase inhibitor, and in cystic fibrosis patients the number and activity of nasal epithelial Na(+)-K(+)-ATPase pumps is increased. 2. We have performed a series of studies to determine whether drugs which modify airway epithelial Na(+)-K(+)-ATPase activity in vitro can modify nasal potential in cystic fibrosis patients in vivo. As transepithelial nasal potential difference measurements were used to study the effect of drug modulation of airway epithelial ion transport in vivo, the repeatability of the technique was first evaluated. In order to assess the effectiveness of the technique used for measuring nasal potential difference, a pilot study was carried out using topical amiloride, a drug which has previously been shown to inhibit airway epithelium sodium transport in vivo. We then studied the effects of ouabain and digoxin, two inhibitors of Na(+)-K(+)-ATPase, on nasal potential difference. 3. In study 1, nasal potential difference measurements were repeated on non-consecutive days in 20 patients with cystic fibrosis and 20 healthy individuals. Healthy subjects had a mean (SEM) potential difference value of -19.5 (0.9) mV with a 95% range for a single estimate of 75-133%. In patients with cystic fibrosis, the mean (SEM) potential difference was -40.4, (2.1) mV, with a 95% range for a single estimate of 74-136%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Signal-averaged electrocardiography of the sinus and paced P wave in sinus node disease.

The detection of paroxysmal atrial fibrillation (AF) in patients requiring a permanent pacemaker for sinus node disease may influence the choice of both pacemaker and programmed mode. While signal-averaged ECG of the P wave (SAEP) during sinus rhythm may detect patients with paroxysmal AF, the value of SAEP in the presence of sinus node disease is unknown. We therefore evaluated SAEP in patients with sinus node disease during sinus rhythm and atrial pacing. We investigated 10 patients with sinus node disease alone (SND), 10 with sinus node disease and paroxysmal AF (SND-PAF), and 20 normal controls (NC) using a P wave specific, signal-averaging system. In sinus rhythm, duration and energy were greater in SND-PAF than in SND and NC (mean [SEM] duration: 153 [4] msec, 140 [4] msec, and 134 [2] msec, P < 0.001; energy from 20-150 Hz: 76 [18] muV2.sec, 48 [7] muV2.sec, and 36 [3] muV2.sec, P = 0.006). Atrial pacing in SND-PAF produced an 11% prolongation of atrial activation but little further abnormality in P wave characteristics. In SND, atrial pacing caused a 20% prolongation of the P wave and increased P wave energy to a greater extent than in SND-PAF. We conclude that in patients with SND, atrial activation appears similar to normal controls during sinus rhythm but changes significantly on pacing. In patients with SND-PAF, atrial activation is abnormal during sinus rhythm with little further change when the atrium is paced. SAEP may be useful in detecting a predisposition to paroxysmal AF in the presence of sinus node disease and might help optimize pacemaker prescription.

Adult↗
PubMed1995

Prospective study of risk factors for early and persistent wheezing in childhood.

The object of this study was to determine the relative importance of low birth weight, preterm birth, low maternal age, household size, exposure to maternal smoking, personal smoking at 16 yrs of age, early termination of breastfeeding and socioeconomic status in the aetiology of wheezing illness in the first 5 yrs of life, and on the persistence of this illness at 16 yrs of age. In 15,712 children born in Britain during one week of April 1970, the occurrence of wheezing by 5 yrs of age, and of wheezing in the past year at 16 yrs of age within this group were analysed in multivariate logistic regression against each potential risk factor. The independent determinants of wheezing by 5 yrs of age were male sex, maternal smoking during pregnancy (odds ratio (OR) for 15+ cigarettes.day-1 = 1.39; 95% confidence interval (95% CI) 1.22-1.58) and low birthweight (OR for birthweight < 2.5 kg = 1.26; 95% Cl 1.07-1.50). Of children who had wheezed by 5 yrs of age, 15% reported wheezing in the past 12 months at 16 yrs of age. The persistence of symptoms at 16 yrs of age was independently related to low maternal age (OR for 20 vs 40 yrs of age = 1.96; 95% CI 1.08-3.45) and to high social status (OR for most vs least advantaged = 1.95; 95% CI 1.13-3.38). We conclude that low birth weight and maternal smoking in pregnancy are independent risk factors for early childhood wheezing, but in 85% of children with early wheezing it resolves by 16 yrs of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Increased intracerebral cerebrospinal fluid spaces predict unemployment and negative symptoms in psychotic illness. A prospective study.

BACKGROUND: It has been suggested that the dimensions of cerebral ventricles are a risk factor for poor outcome in psychotic illness. METHOD: A cohort of 140 patients with functional psychoses of recent onset who had undergone CT scanning, were followed up for an average of 46 months and assessed on six dimensions of course and outcome of illness. RESULTS: Left and right sylvian fissure volumes and, to a lesser extent, third ventricular volume predicted negative symptoms and unemployment over the course of follow-up, the latter association being mediated by poor cognitive functioning. There was significant linear trend in risk over the distribution of sylvian fissure volumes in the cohort, and associations were especially evident in schizophrenic patients. No associations were found with global severity of illness, duration of hospital stay, homelessness, or affective symptoms. CONCLUSIONS: These findings support the notion that dimensions of the cerebral ventricles are a continuous risk factor for some measures of outcome in the functional psychoses.

Arousal↗