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Biomedical subjects

R D Barr

Publications and source records attributed to R D Barr.

At least 19 recordsLinked to original sources
PubMed2005

Use of paediatric versus adult oncology treatment centres by adolescents 15-19 years old: the Canadian Childhood Cancer Surveillance and Control Program.

The aim of this study was to evaluate the treatment patterns of adolescents with cancer in Canada to ensure this population is receiving the most appropriate care. The Treatment and Outcome Surveillance (TOS) system was compared with the Canadian Cancer Registry (CCR) to estimate the proportion of adolescents (15-19 years) treated in Canadian paediatric oncology centres from 1995 to 2000 inclusive. Using TOS, the demographic, disease, and clinical characteristics of adolescents treated in paediatric versus adult centres in the Prairies were compared and differences were tested statistically. Approximately 30% of Canadian adolescents with cancer were treated in a paediatric centre. Adolescents treated in an adult centre were older at diagnosis and more likely to have carcinoma or germ cell tumours. The time between symptom onset and first treatment was longer for these adolescents, primarily due to the time between first health-care contact and assessment by a treating oncologist or surgeon. They were less likely to be enrolled in a clinical trial. These results suggest that care for adolescents with cancer in Canada is less satisfactory than for younger children, and can be improved.

Adolescent↗
PubMed2005

Alendronate for steroid-induced osteopenia in children with acute lymphoblastic leukaemia or non-Hodgkin's lymphoma: results of a pilot study.

BACKGROUND/OBJECTIVES: Osteopenia is a significant morbidity in children undergoing therapy for acute lymphoblastic leukaemia (ALL) or non-Hodgkin's lymphoma (NHL). We conducted a pilot study to assess the impact of alendronate on whole body bone mineral content (WB-BMC), lumbar spine bone mineral density (LS-BMD), biochemical measures of bone mineral metabolism, as well as gross motor function and health-related quality of life (HRQL) in children undergoing therapy for ALL or NHL. METHODS: Ten children (nine boys) between the ages of 3.6 and 14.6 years, on identical maintenance chemotherapy for ALL or NHL were treated with oral alendronate once weekly, and daily calcium supplementation, for a period of six months. Outcome measures were WB-BMC and LS-BMD; biochemical measures of bone mineral metabolism including plasma osteocalcin, C-terminal telopeptide of type I collagen (CTx), serum calcium, 25-hydroxy-vitamin D (25-OHD), and parathyroid hormone (PTH); as well as assessments of motor function and HRQL. RESULTS: A gain in Z score was observed in 7/9 evaluable patients for WB-BMC (mean increase of 0.49) and LS-BMD (0.51). Plasma osteocalcin and CTx showed a change in bone turnover favouring formation over resorption. Serum calcium and 25-OHD remained normal throughout treatment. After an initial spike, serum PTH returned to baseline values at week 4. Measures of motor function showed some improvement and there were modest gains in HRQL. CONCLUSIONS: Alendronate therapy was tolerated well. Further study in a larger sample of children with ALL or NHL is warranted, in the context of a randomized clinical trial.

Absorptiometry, Photon↗
PubMed2004

Health status of young children during therapy for advanced neuroblastoma.

BACKGROUND: The purpose of this study was to describe the health status experienced by young children during various phases of therapy for advanced neuroblastoma. METHODS: Nineteen patients aged 2.00-4.99 years at the time of diagnosis of neuroblastoma (stages 3 or 4) who received active therapy between 1996 and 2000 were enrolled on the study. Their parents provided proxy assessments of their health status at a maximum of 10 assessment points during therapy using the Comprehensive Health Status Classification System for Pre-school Children (CHSCS-PS), which assesses level of function on 10 separate health domains. RESULTS: Eighty-six assessment questionnaires were completed. Maximum morbidity was reported immediately following diagnosis and in the 2-3 weeks following bone marrow transplantation. The greatest morbidity was observed in the pain, self-care, mobility, and emotion domains. CONCLUSIONS: In addition to facing a high risk of mortality, young children being treated for advanced neuroblastoma also experience considerable morbidity.

Child, Preschool↗
PubMed2004

Inter-observer agreement of a comprehensive health status classification system for pre-school children among patients with Wilms' tumor or advanced neuroblastoma.

We assessed inter-observer agreement on a new comprehensive health status classification system for preschool children (CHSCS-PS). Prospective assessments of children aged 2-4.9 years at the time of diagnosis of neuroblastoma (stages 3-4, excluding 4S) or Wilms' tumor (stages II-V) were collected independently from a parent and nurse by self-report during therapy. Responses were used to determine functional status on 10 health domains, as well as an overall disability score. Inter-observer agreement was evaluated by a kappa statistic for agreement about levels within individual domains, and by an intraclass correlation coefficient (ICC) for agreement of overall disability scores. Twenty-four parent/nurse pairs of assessments were collected. Agreement was almost perfect for mobility and self-care, substantial for emotion and pain, and slight for speech. There was high percent agreement for vision, hearing, dexterity, learning and remembering, and thinking and problem solving, but insufficient variability in responses to calculate a kappa statistic. The ICC for overall disability scores between observers was 0.86, indicating strong agreement. Given the need for, and paucity of, instruments for the measurement of health-related quality of life in very young children, these results strongly support further evaluation of the CHSCS-PS.

Child, Preschool↗
PubMed2001

Improved outcome for children with acute lymphoblastic leukemia: results of Dana-Farber Consortium Protocol 91-01.

The Dana-Farber Cancer Institute (DFCI) acute lymphoblastic leukemia (ALL) Consortium Protocol 91-01 was designed to improve the outcome of children with newly diagnosed ALL while minimizing toxicity. Compared with prior protocols, post-remission therapy was intensified by substituting dexamethasone for prednisone and prolonging the asparaginase intensification from 20 to 30 weeks. Between 1991 and 1995, 377 patients (age, 0-18 years) were enrolled; 137 patients were considered standard risk (SR), and 240 patients were high risk (HR). Following a 5.0-year median follow-up, the estimated 5-year event-free survival (EFS) +/- SE for all patients was 83% +/- 2%, which is superior to prior DFCI ALL Consortium protocols conducted between 1981 and 1991 (P =.03). There was no significant difference in 5-year EFS based upon risk group (87% +/- 3% for SR and 81% +/- 3% for HR, P =.24). Age at diagnosis was a statistically significant prognostic factor (P =.03), with inferior outcomes observed in infants and children 9 years or older. Patients who tolerated 25 or fewer weeks of asparaginase had a significantly worse outcome than those who received at least 26 weeks of asparaginase (P <.01, both univariate and multivariate). Older children (at least 9 years of age) were significantly more likely to have tolerated 25 or fewer weeks of asparaginase (P <.01). Treatment on Protocol 91-01 significantly improved the outcome of children with ALL, perhaps due to the prolonged asparaginase intensification and/or the use of dexamethasone. The inferior outcome of older children may be due, in part, to increased intolerance of intensive therapy.

Adolescent↗
PubMed2001

Magnesium absorption using stable isotope tracers in healthy children and children treated for leukemia.

Intestinal magnesium (Mg) absorption was measured in six healthy children (control) and in four children treated for acute lymphoblastic leukemia with the single-isotope fecal recovery technique (SIFRT). The objective of this study was to determine Mg absorption in young children with acute lymphoblastic leukemia using stable isotope tracers. Fractional and absolute absorption levels determined by SIFRT were not significantly different between children with acute lymphoblastic leukemia (fractional absorption: 58.3 +/- 10.6% [mean +/- SEM], absolute absorption: 3.66 +/- 0.71 mg x kg(-1) x d(-1), [0.15 +/- 0.03 mmol x kg(-1) x d(-1)]) and control children (fractional absorption: 61.4 +/- 7.5%, absolute absorption: 5.69 +/- 0.85 mg x kg(-1) x d(-1), [0.23 +/- 0.03 mmol x kg(-1) x d(-1)]). Average Mg absorption in young children (aged 3--8 y) was 60.2 +/- 5.8%. This study describes the first application of the SIFRT to assess Mg absorption in young children and illustrates the feasibility of the SIFRT in this age group to obtain more accurate information on Mg absorption.

Case-Control Studies↗
PubMed2001

The Health Utilities Index (HUI) system for assessing health-related quality of life in clinical studies.

This paper reviews the Health Utilities Index (HUI) systems as means to describe health status and obtain utility scores reflecting health-related quality of life (HRQoL). The HUI Mark 2 (HUI2) and Mark 3 (HUI3) classification and scoring systems are described. The methods used to estimate multiattribute utility functions for HUI2 and HUI3 are reviewed. The use of HUI in clinical studies for a wide variety of conditions in a large number of countries is illustrated. HUI provides a comprehensive description of the health status of subjects in clinical studies. HUI has been shown to be a reliable, responsive and valid measure in a wide variety of clinical studies. Utility scores provide an overall assessment of the HRQoL of patients. Utility scores are also useful in cost-utility analyses and related studies. General population norm data are available. The widespread use of HUI facilitates the interpretation of results and permits comparisons. HUI is a useful tool for assessing health status and HRQoL in clinical studies.

Cost-Benefit Analysis↗
PubMed2001

Health status and health-related quality of life in survivors of cancer in childhood in Latin America: a MISPHO feasibility study.

Cancer is an increasing cause of disease-related death in childhood within developing countries, where the great majority of the world's children reside. The improving prospects for survival in such children, and the corresponding challenge of undertaking economic evaluations of related health interventions, provide a stimulus to study the health-status and health-related quality of life in survivors of cancer in childhood in Latin America. Spanish language versions of questionnaires for proxy assessors, based on the Health Utilities Index (HUI), were used to elicit responses from parents and physicians. The HUI is a family of multi-attribute, generic, preference-linked measures of health status and health-related quality of life that are reliable, responsive and valid, and have been used previously in pediatric oncology. Valid responses were received from 178 parents and 144 physicians in 6 centres in 4 countries (Cuba, Honduras, Colombia and Uruguay). For children with acute lymphoblastic leukemia the major morbidity burdens were in the attributes of emotion, cognition and pain. The overall burden of morbidity was greater in children with non-Hodgkin's lymphoma. In survivors of Hodgkin's disease and Wilms' tumor the attributes most affected were emotion and pain. In general, there was considerable agreement between the assessments provided independently by parents and physicians. This study demonstrates the feasibility of conducting such measurements in developing countries, and reveals similarities in health status and health-related quality of life to comparable populations in more privileged societies.

Child↗
PubMed2000

Health-related quality of life in survivors of Wilms' tumor and advanced neuroblastoma: aA cross-sectional study.

PURPOSE: In pediatric oncology, Wilms' tumor and advanced neuroblastoma represent opposite ends of the spectra of survival probability and therapeutic intensity. Consequently, it was envisaged that survivors of Wilms' tumor would enjoy better health status and health-related quality of life (HRQL) than survivors of advanced neuroblastoma. PATIENTS AND METHODS: Health status questionnaires were sent to the parents of all eligible children and to the children themselves if they were > or = 8 years of age. Responses were received from 84% of 93 eligible families. Responses were converted by established algorithms into levels of two multiattribute health status classification systems known as Health Utilities Index Mark 2 and Mark 3. These systems are linked to measures of preference, in the form of multiattribute utility functions, which provide scores of morbidity for single-attribute levels and of global HRQL for comprehensive health states. RESULTS: A greater burden of morbidity was identified in the survivors of advanced neuroblastoma than in survivors of Wilms' tumor based on the assessments of the parents of these children. In particular, survivors of advanced neuroblastoma exhibited deficits in hearing and speech. It is possible that this morbidity burden reflects the prevalent use of platinum compounds (causing ototoxicity) in this group. Within parent-child dyads there was a high level of percentage agreement on responses in all attributes except cognition. CONCLUSION: Extension of this study to a larger sample size of patients will provide clarification of these observations.

Adolescent↗
PubMed2000

German cross-cultural adaptation of the Health Utilities Index and its application to a sample of childhood cancer survivors.

UNLABELLED: Steady progress in developing effective treatments for childhood cancer and other severe pediatric diseases has established the need to consider the nature and frequency of late physical and psychological effects. The Health Utilities Index Mark 2 and Mark 3 (HUI2/3) systems were developed by Feeny, Furlong, Torrance et al. in Canada. These systems are generic multi-attribute measures of a person's health status and health-related quality of life. The first German version of the Canadian HUI2/3 questionnaire was created in our clinic, following recommended guidelines for cross-cultural adaptation of health-related quality of life measures. The usefulness of the resultant version was investigated using a sample of 142 patients who presented to our oncological outpatients' department for a routine health care visit after completion of treatment. The 15 items of the HUI2/3-questionnaire were answered independently by three groups of assessors--nurses, physicians, and parents or patients. Two additional questions covered ratings of the severity of treatment effects and the specification of these effects. The questionnaire was both easy to use and acceptable to the assessors. Percentage agreement between observers about levels for individual attributes ranged from 56% to 100%, with the lowest agreement on the subjective attributes of emotion, pain and cognition. These results are in accordance with previous studies using the original instrument. HUI2 global utility scores were significantly related to ratings of treatment sequelae, giving support to the discriminant validity of the measure. CONCLUSION: The German version of HUI2/3 is a useful instrument with generally high inter-observer agreement and good suitability for outcome measurement in childhood cancer patients. Further research is needed to assess the usefulness of the instrument in other clinical populations and its sensitivity in longitudinal studies.

Child↗
PubMed2000

Results of Dana-Farber Cancer Institute Consortium protocols for children with newly diagnosed acute lymphoblastic leukemia (1981-1995).

The Dana-Farber Cancer Institute (DFCI) ALL consortium has been conducting clinical trials in childhood acute lymphoblastic leukemia (ALL) since 1981. The treatment backbone has included intensive, multi-agent remission induction, early intensification with weekly, high-dose asparaginase, cranial radiation for the majority of patients, frequent vincristine/ corticosteroid pulses during post-remission therapy, and for high-risk patients, doxorubicin during intensification. Between 1981 and 1995, 1,255 children with newly diagnosed ALL were evaluated on four consecutive protocols: 81-01 (1981-1985), 85-01 (1985-1987), 87-01 (1987-1991) and 91-01 (1991-1995). The 5-year event-free survival (EFS) rates (+/- standard error) for all patients by protocol were as follows: 74 +/- 3% (81-01), 78 +/- 3% (85-01), 77 +/- 2% (87-01) and 83 +/- 2% (91-01). The 5-year EFS rates ranged from 78 to 85% for patients with B-progenitor phenotype retrospectively classified as NCI standard-risk, 63-82% for NCI high-risk B-progenitor patients, and 70-79% for patients with T cell phenotype. Results of randomized studies revealed that neither high-dose methotrexate during induction (protocol 87-01) nor high-dose 6-mercaptopurine during intensification (protocol 91-01) were associated with improvement in EFS compared with standard doses. Current studies continue to focus on improving efficacy while minimizing acute and late toxicities.

Adolescent↗
PubMed1999

Induction failure in acute lymphoblastic leukemia of childhood.

BACKGROUND: Although it is widely accepted that failure to achieve complete remission (CR) portends a poor prognosis in childhood acute lymphoblastic leukemia (ALL), there is variability in the precise definition of induction failure and, to the authors' knowledge, few published data exist regarding the outcome of patients who are slow to achieve CR. METHODS: Between 1987-1995, 774 children with ALL were treated on 2 consecutive protocols and were evaluable to assess the time required to attain CR. The authors compared presenting characteristics and outcomes of patients based on their remission status after 1 month of induction chemotherapy: CR (n = 656), protracted hypoplasia (low peripheral blood counts and/or hypocellular marrow) (n = 95), and persistent leukemia (M2 or M3 bone marrow and/or evidence of extramedullary leukemia) (n = 23). The median follow-up was 5.2 years. RESULTS: Presenting features that predicted persistent leukemia included a leukocyte count > 100,000/mm3 and T-cell phenotype. Approximately 91% of patients with persistent leukemia and 100% with protracted hypoplasia eventually achieved CR. The 5-year event free survival (EFS) (95% confidence intervals [95% CI] in parentheses) for patients with persistent leukemia after 1 month was 16% (95% CI, 0%, 31%), which was significantly worse (P < 0.001) than that for those who achieved CR within 1 month (5-year EFS, 82%; 95% CI, 79%, 86%) and that for those with protracted hypoplasia (5-year EFS, 79%; 95% CI, 70%, 87%). For patients with persistent leukemia, there was no significant difference in survival based on bone marrow status (M2 or M3) after 1 month or on the number of induction cycles received before achieving CR. CONCLUSIONS: Patients with persistent leukemia at the end of 1 month of therapy have a dismal prognosis, regardless of when they subsequently achieve CR. More intensive and/or novel therapies should be considered for this subset of patients.

Adolescent↗
PubMed1999

Limitation of ankle range of motion in survivors of acute lymphoblastic leukemia: a cross-sectional study.

BACKGROUND: The purpose of this study was to evaluate and determine the factors related to active and passive dorsiflexion range of motion (DF-ROM) in survivors of acute lymphoblastic leukemia (ALL), which is the most obvious impairment of musculoskeletal function in such children. PROCEDURE: The subjects included 54 survivors of ALL treated on Dana-Farber Cancer Institute protocols and 54 comparable healthy children. Bilateral active and passive DF-ROM were measured with the knee extended. RESULTS: The survivors of ALL had significantly less active and passive DF-ROM (6.4 vs. 16.8, 10.5 vs. 18.8 degrees, respectively, P < 0.001) than the comparison children. Weight for age at the time of assessment and change in height during treatment showed significant negative correlations with DF-ROM. Length of time-off treatment was not associated with DF-ROM. CONCLUSIONS: Multiple regression analyses identified the variables of age at diagnosis and gender as significant predictors of both DF-ROM measures following treatment. Children diagnosed at a younger age and females were at greater risk for restricted DF-ROM. Close monitoring and preventative therapy programs for this complication are warranted for children, especially young girls receiving treatment for ALL.

Adolescent↗