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Biomedical subjects

P M Fayers

Publications and source records attributed to P M Fayers.

At least 19 recordsLinked to original sources
PubMed2002

Fetal, infant, and childhood growth and adult blood pressure: a longitudinal study from birth to 22 years of age.

BACKGROUND: People who are small at birth tend to have higher blood pressure in later life. However, it is not clear whether it is fetal growth restriction or the accelerated postnatal growth that often follows it that leads to higher blood pressure. METHODS AND RESULTS: We studied blood pressure in 346 British men and women aged 22 years whose size had been measured at birth and for the first 10 years of life. Their childhood growth was characterized using a conditional method that, free from the effect of regression to the mean, estimated catch-up growth. People who had been small at birth but who gained weight rapidly during early childhood (1 to 5 years) had the highest adult blood pressures. Systolic pressure increased by 1.3 mm Hg (95% CI, 0.3 to 2.3) for every standard deviation score decrease in birth weight and, independently, increased by 1.6 mm Hg (95% CI, 0.6 to 2.7) for every standard deviation score increase in early childhood weight gain. Adjustment for adult body mass index attenuated the effect of early childhood weight gain but not of birth weight. Relationships were smaller for diastolic pressure. Weight gain in the first year of life did not influence adult blood pressure. CONCLUSIONS: Part of the risk of adult hypertension is set in fetal life. Accelerated weight gain in early childhood adds to this risk, which is partly mediated through the prediction of adult fatness. The primary prevention of hypertension may depend on strategies that promote fetal growth and reduce childhood obesity.

Adult↗
PubMed2002

Cluster-randomized trials.

Cluster-randomized trials represent an important experimental design, supplementing ordinary randomized clinical trials. They are particularly relevant when evaluating interventions at the level of clinic, hospital, district or region. They are necessary when it is not feasible to randomize individual patients, and desirable when there may be contamination between clusters. But they also carry serious design and analysis implications, and the use of clusters as the unit of randomization must be justified. Sample sizes will usually need to be greatly increased, an adequate number of clusters is essential, and the statistical analysis must allow for the cluster design. And one should rigorously guard against selection bias.

Bias↗
PubMed2002

Lack of concealment may lead to selection bias in cluster randomized trials of palliative care.

Comprehensive palliative care programs are often implemented on a community level, and to evaluate such interventions, randomization by cluster (community) may be the only feasible method. In trials randomizing individual subjects, the importance of proper concealment has been stressed. In cluster randomized trials, however, concealment of individual patient allocation is often impossible. The following risk of selection bias has been given little attention. In the present study, comparing palliative care to conventional care, community health care districts were defined as clusters and randomized. The patients' treatment assignment was determined by the allocation of the cluster in which they resided, and hence predictable by their address. A biased selection based on practical considerations related to patients' diagnoses and hospital departments was suspected. To explore this, cancer diagnoses were grouped according to local tradition for sharing of treatment responsibility among hospital departments. A significant difference between trial arms in distribution of these groups was revealed and strongly supported our suspicion. The finding carries an important message to future researchers: when using cluster randomization, any evidence of selection bias should be carefully checked and reported.

Adult↗
PubMed2000

Analysis of messy longitudinal data from a randomized clinical trial. MRC Lung Cancer Working Party.

The randomized clinical trial, LU19, conducted by the Medical Research Council Lung Cancer Working Party, was designed to compare ACE (doxorubicin, cyclophosphamide and etoposide) chemotherapy plus G-CSF (granulocyte colony-stimulating factor) at 2-week intervals versus ACE chemotherapy alone at standard 3-week intervals in patients with small-cell lung cancer. This trial investigated whether more intensive administration of ACE would improve overall survival and affect the quality of life of patients. The report on overall survival and other outcome measures will be published in the Journal of Clinical Oncology. In this paper we focus on methods of analysing aspects of data reflecting quality of life. Twelve symptoms of lung cancer and its treatment - cough, haemoptysis, pain, nausea, vomiting, hoarse voice, sore mouth, rash, lethargy, lack of appetite, alopecia, and dysphagia - were scheduled to be assessed on seven occasions for the ACE arm and on eight occasions for the ACE+G-CSF arm by clinicians during the first 18 weeks of the treatment period. However, in practice the number of assessment forms completed per patient ranged from 1 to 9, and assessment time-points were very different from those planned. These 'messy' longitudinal data are explored by both a summary measure approach, in which experience of a symptom is summarized by a single value, and an extensive model-based statistical approach, which explicitly takes into account correlation within repeated measures. These analyses provide a clear picture of symptom comparisons between the two treatments. The application of various methods offers not only an approach to assessing the robustness of the results but also a basis for investigating reasons for inconsistency of results across methods. We conclude that except lethargy, which is worse in the ACE+G-CSF arm, all symptoms are similar across the two arms during the treatment period.

Amsacrine↗
PubMed2000

A 12 country field study of the EORTC QLQ-C30 (version 3.0) and the head and neck cancer specific module (EORTC QLQ-H&N35) in head and neck patients. EORTC Quality of Life Group.

This study tests the reliability and validity of the European Organization for Research and Treatment of Cancer (EORTC) head and neck cancer module (QLQ-H&N35) and version 3.0 of the EORTC Core Questionnaire (QLQ-C30) in 622 head and neck cancer patients from 12 countries. The patients completed the QLQ-C30, the QLQ-H&N35 and a debriefing questionnaire before antineoplastic treatment or at a follow-up. 232 patients receiving treatment completed a second questionnaire after treatment. Compliance was high and the questionnaire was well accepted by the patients. Multitrait scaling analysis confirmed the proposed scale structure of the QLQ-H&N35. The QLQ-H&N35 was responsive to differences between disease status, site and patients with different Karnofsky performance status, and to changes over time. The new physical functioning scale (with a four-point response format) of version 3.0 of the QLQ-C30 was shown to be more reliable than previous versions. Thus, the QLQ-H&N35, in conjunction with the QLQ-C30, appears to be reliable, valid and applicable to broad multicultural samples of head and neck cancer patients.

Adult↗
PubMed2000

Sample size calculation for clinical trials: the impact of clinician beliefs.

The UK Medical Research Council (MRC) randomized trial of gastric surgery, ST01, compared conventional (D1) with radical (D2) surgery. Sample size estimation was based upon the consensus opinion of the surgical members of the design team, which suggested that a change in 5-year survival from 20% (D1) to 34% (D2) could be realistic and medically important. On the basis of these survival rates, the sample size for the trial was 400 patients. However, this trial was exceptional in the way that a survey of surgeons' opinions was made at the start of the trial, in 1986, and again before results were analysed but after termination of the trial in 1994. At the initial survey, the three surgeons from the trial steering committee and 23 other surgeons experienced in treating gastric carcinoma were given detailed questionnaires. They were asked about the expected survival rate in the D1 group, anticipated difference in survival from D2 surgery, and what difference would be medically important and influence future treatment of patients. The consensus opinion of those surveyed was that there might be a survival improvement of 9.4%. In 1994, prior to closure of the trial, and before any survival information was disclosed, the survey was repeated with 21 of the original 26 surgeons. At this second survey, the opinion of the trial steering committee was that 9.5% difference was more realistic. This was in accord with the opinion of the larger group, which remained little changed since 1986. The baseline 5-year D1 survival was thought likely to be about 32%, which corresponded closely to the actual survival of recruited patients. Revised sample size calculations suggested that, on the basis of these more recent opinions, between 800 and 1200 patients would have been required. Both surveys assessed the level of treatment benefit that was deemed to be sufficient for causing surgeons to change their practice. This showed that the 13% difference in survival used as the study target was clinically relevant, but also indicated that many clinicians would remain unwilling to change their practice if the difference is only 9.5%. The experience of this carefully designed trial illustrates the problems of designing long-term, randomized trials. It raises interesting questions about the common practice of basing sample size estimates upon the beliefs of a trial design committee that may include a number of enthusiasts for the trial treatment. If their opinion of anticipated effect sizes drives the design of the trial, rather than the opinion of a larger community of experts that includes sceptics as well as enthusiasts, there is likely to be a serious miscalculation of sample size requirements.

Bayes Theorem↗
PubMed2000

The CUP trial: a randomized study analyzing the efficacy of high dose therapy and purging in low-grade non-Hodgkin's lymphoma (NHL).

BACKGROUND: The CUP trial was initiated to analyze the value of high-dose therapy and stem-cell transplantation and purging in patients with relapsed chemosensitive follicular NHL. PATIENTS AND METHODS: After three cycles of chemotherapy responsive patients were randomized to either three more cycles of the same chemotherapy (C), high-dose therapy followed by autologous unpurged (U) or purged (P) stem-cell transplantation. Purging was performed using a cocktail of monoclonals. Pretransplant conditioning consisted of cyclophosphamide (60 mg/kg x 2) and total body irradiation. RESULTS: Of the 140 patients registered from 26 centers in Europe, 89 fulfilled the criteria for randomization (C: 24, U: 33 and P: 32). Reasons for failure to randomize were: no response (28), persistent marrow infiltration (4), patient refusal (7), other (7), no data (5). With the current follow up (median 26 months from randomization) 16 (66%) in C are known to have progressed or relapsed, in contrast to 13 (39%) of U and 12 (37%) of the P patients (P-value 0.002). Overall survival is premature with the current available data. CONCLUSIONS: Patients in U and P arms had higher progression/relapse-free survival rate. There are some suggestions of some improvement in overall survival rate.

Adult↗
PubMed1999

Anxiety and depression in breast cancer patients at low risk of recurrence compared with the general population: a valid comparison?

Breast cancer and its treatment have been associated with psychological morbidity. In this study our aim was to quantify the excess anxiety and depression resulting from breast cancer. We compared 538 newly diagnosed breast cancer patients at low risk of recurrence (87.0% responded) to 872 women randomly selected from the Danish general population (69.7% responded) using the Hospital Anxiety and Depression Scale (HADS). Contrary to expectations, the proportions classified as "cases" of anxiety and depression were not significantly different in the two groups. The breast cancer patients' mean HADS scores were significantly lower than those in the general population sample (anxiety, P = 0.021; depression, P < 0.001), indicating less anxiety and depression. However, we question the validity of this comparison. The HADS may not be suitable for use in the general population and there may be methodological problems in comparisons of groups whose life situations are very different.

Adult↗
PubMed1999

The course of anxiety and depression during the first year after allogeneic or autologous stem cell transplantation.

Psychological distress is frequently reported in transplant survivors. We prospectively assessed anxiety and depression before transplant, in the isolation period and during a follow-up period of 1 year. The Hospital Anxiety and Depression Scale (HADS) was administered to 131 cancer patients treated with high-dose chemotherapy followed by allogeneic (SCT) or autologous (ASCT) stem cell transplantation, and a concurrent group of 123 lymphoma patients receiving standard chemotherapy (CT) who served as a reference group. Relatively low levels of anxiety and depression were found. The level of anxiety slightly declined from baseline during follow-up (mean scores SCT: from 5.3 to 3.6, CT: from 6.0 to 4.2) or remained fairly stable (ASCT: from 5.4 to 4.8). The level of depression peaked when the transplant patients were in protective isolation or shortly thereafter (SCT: 6.1, ASCT: 6.4), but stabilized at baseline levels after 4 months. The highest level of depression in the CT group was reported 4 months after start of chemotherapy (3.4). Elevated levels of anxiety and depression at baseline predicted more anxiety and depression at the later assessments (P values < 0.0001). The ASCT group had higher levels of anxiety after 1 year (mean 4.8) than those found in the other two groups (SCT: 3.6, CT: 4.2), although they were not statistically significant. This study revealed lower than expected levels of anxiety and depression after intensive chemotherapy followed by SCT or ASCT. There was a decline in psychological distress during the 1-year follow-up period.

Adolescent↗
PubMed1999

Health-related quality of life 1 year after allogeneic or autologous stem-cell transplantation: a prospective study.

PURPOSE: To evaluate health-related quality of life (HRQOL) in adults treated with high-dose chemotherapy followed by allogeneic (SCT) and autologous (ASCT) stem-cell transplantation 1 year after transplantation, using data from concurrent lymphoma patients receiving combination chemotherapy (CT) as a reference. MATERIALS AND METHODS: Forty-one leukemia patients (SCT group), 51 lymphoma patients (ASCT group), and 85 CT patients completed the European Organization for Research and Treatment of Cancer QLQ-C30 questionnaire at baseline and after 1 year. RESULTS: The SCT group (median age, 36 years) had better functioning scores and less symptomatology at baseline compared with the ASCT (median age, 41 years) and CT (median age, 37 years) groups. Statistically significant differences of 10 or more points on the 0 to 100 scales were found for 10 of 15 scales and items (P< or =.01) between the SCT and ASCT groups. Global quality of life (79 v 58, P<.0001), role function (83 v 65, P = .001), sleep disturbances (6 v 28, P<.0001), and fatigue (25 v 44, P = .0001) deviated most. The differences were 10 or more points for seven of 15 scales and items comparing the SCT and CT groups, with sleep disturbances (6 v 35, P<.0001) and pain (11 v 29, P<.01) deviating most. Differences across groups were smaller after 1 year; cognitive function was the only scale with a statistically significant difference (ASCT 80 v CT 89; P = .002). Patterns of change in HRQOL scores were different between groups during follow-up. A great improvement was found in the ASCT group (P<.01 for emotional and role function, fatigue, appetite, and constipation), whereas no significant changes were observed for the SCT group. CONCLUSION: Prospective studies with extended follow-up periods are necessary to separate a slow recovery process from more permanently reduced HRQOL after transplantation and to examine the late side effects from previous treatment.

Adolescent↗
PubMed1999

Quality of life in head and neck cancer patients: validation of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-H&N35.

PURPOSE: The aim of this study was to define the scales and test the validity, reliability, and sensitivity of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ)-H&N35, a questionnaire designed to assess the quality of life of head and neck (H&N) cancer patients in conjunction with the general cancer-specific EORTC QLQ-C30. PATIENTS AND METHODS: Questionnaires were given to 500 H&N cancer patients from Norway, Sweden, and the Netherlands as part of two prospective studies. The patients completed the questionnaires before, during (Norway and Sweden only), and after treatment, yielding a total of 2070 completed questionnaires. RESULTS: The compliance rate was high, and the questionnaires were well accepted by the patients. Seven scales were constructed (pain, swallowing, senses, speech, social eating, social contact, sexuality). Scales and single items were sensitive to differences between patient subgroups with relation to site, stage, or performance status. Most scales and single items were sensitive to changes, with differences of various magnitudes according to the site in question. The internal consistency, as assessed by Cronbach's alpha coefficient, varied according to assessment point and within subsamples of patients. A low overall alpha value was found for the speech and the senses scales, but values were higher in assessments of patients with laryngeal cancer and in patients with nose, sinus, and salivary gland tumors. Scales and single items in the QLQ-H&N35 seem to be more sensitive to differences between groups and changes over time than do the scales and single items in the core questionnaire. CONCLUSION: The QLQ-H&N35, in conjunction with the QLQ-C30, provides a valuable tool for the assessment of health-related quality of life in clinical studies of H&N cancer patients before, during, and after treatment with radiotherapy, surgery, or chemotherapy.

Aged↗
PubMed1998

Using reference data on quality of life--the importance of adjusting for age and gender, exemplified by the EORTC QLQ-C30 (+3).

Interpretation of health related quality of life (HRQOL) results in cancer patients is facilitated by knowledge of the levels of HRQOL in the general population. However, direct comparisons can be misleading unless age and gender are considered. We demonstrate the derivation of age- and gender-specific 'expected' values from population reference values by means of simple calculations. This survey included 3000 randomly selected Norwegians above 18 years of age who received the European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire (EORTC QLQ-C30 (+3) by mail. 1965 responses from 2,892 eligible persons (68%) were received. The population was divided into six disease groups based on self-reported health problems. The observed mean scale scores of the different groups deviated greatly from those obtained in the general population. The score for physical function, for example, was 72 for cancer patients and ranged from 73.3 to 82.5 in other disease groups, as opposed to 89.9 in the general population and 98.9 in those with no health problems. The range for one of the quality of life (QOL) scales was 57.7 to 84.7 compared with 73.7 in the general population. Expected mean scores for the patient groups were computed from the reference values, based on the concept of equivalence of age and gender. The differences between the observed mean scores and the reference values were strongly mediated by this method. The expected scores for physical function then ranged from 83.3 to 93.1 and from 70.3 to 75 for the QOL scale. The impact of age and gender on the reference data from the EORTC QLQ-C30 (+3) obtained in a general population shows that these variables must be considered when interpreting data on HRQOL for cancer patients. The demonstration of how to generate mean values which are adjusted according to the age and gender distribution of a population should increase the usefulness of this questionnaire among clinicians.

Adult↗
PubMed1998

Testing for differences in multiple quality of life dimensions: generating hypotheses from the experience of hospital staff.

In clinical trials with a quality of life (QoL) component, it is usual to monitor several QoL dimensions at several points in time. Multiple significance tests without formal hypotheses are problematic. It is not always feasible to specify a priori hypotheses for all variables. Can such studies be used to generate hypotheses for testing in later research only? We developed a method which can allow for formal hypothesis testing on a data set collected without a priori hypotheses in the protocol. We surveyed experienced physicians and nurses treating patients, to obtain independent expectations about differences in QoL dimensions. These 'staff expectations' will be used in the analysis of QoL data collected from breast cancer patients taking part in three randomized trials of adjuvant therapy. We propose frameworks for the informal and formal use of the experience of the staff in testing for group differences in patients' QoL scores. The method described here is anticipated to be useful for QoL studies in general, even when a priori hypotheses were specified before the studies were initiated.

Bayes Theorem↗
PubMed1998

Health-related quality of life in the general Norwegian population assessed by the European Organization for Research and Treatment of Cancer Core Quality-of-Life Questionnaire: the QLQ=C30 (+ 3).

PURPOSE: To obtain reference data on health-related quality of life (HRQOL) for the functional and symptom scales and single items of the European Organization for Research and Treatment of Cancer Core Quality-of-Life Questionnaire (EORTC QLQ-C30 [+ 3]) in a representative sample of the Norwegian general population. PATIENTS AND METHODS: A randomly selected sample of 3,000 people from the Norwegian population, aged 18 to 93 years, who represent geographic diversity, took part in this postal survey. The EORTC QLQ-C30 (+ 3) and a questionnaire about demographic data and health were sent by mail. A new questionnaire package was sent as a reminder after 3 weeks. RESULTS: The survey yielded a high response rate with 1,965 of 2,892 eligible persons responding (68%). There was a low amount of missing data (1.8%). Internal consistency was highly satisfactory and yielded Cronbach's alpha coefficients greater than 0.70 for all but two functional scales and one symptom scale. The sensitivity of the questionnaire was shown by the excellent discrimination between age and sex groups. Clinical validity was shown by the distinct differences according to age and sociodemographic characteristics. Women reported lower functional status and global quality of life (mean scale scores from 71.7 to 91.0) than men (mean scale scores from 75.4 to 94.4), and also more symptoms and problems. This was remarkably consistent across age groups, as was a decline in functional status with an increase in age. CONCLUSION: This is the first study that presented reference data from the EORTC QLQ-C30 (+ 3) in a sample from a general population and seems to provide valid measures of HRQOL within different age groups. The results may serve as a guideline for clinicians when interpreting HRQOL in their own groups of patients, and contributes to a better understanding of the significance of mean scores and their clinical relevance.

Adult↗
PubMed1997

Tutorial in biostatistics Bayesian data monitoring in clinical trials.

Many clinical trials organizations use regular interim analyses to monitor the accruing results in large clinical trials. In disease areas such as cancer, where survival is usually a major outcome variable, ethical considerations may lead to a stipulated requirement for data monitoring of mortality. This monitoring has frequently taken the form of limiting interim analyses to be few in number, and specifying an extreme p-value of, for example, p < 0.001 or p < 0.01 as grounds for early termination of the trial. Group-sequential methods are also used. However, none of these approaches formally assesses the impact that the results of a clinical trial may have upon clinical practice. Thus a trial might be terminated early because of apparent treatment benefits, but might fail to influence sceptical clinicians to modify their future treatment policy. We discuss the application of Bayesian methods, including the use of uninformative, sceptical and enthusiastic priors, and demonstrate that the necessary calculations are both straightforward to perform and easy to interpret statistically and clinically. Methods are illustrated with interim analyses of a clinical trial in oesophageal cancer.

Bayes Theorem↗