Biomedical subjects

Jane L Hutton

Publications and source records attributed to Jane L Hutton.

9 recordsLinked to original sources

PubMed2006

Maximising response to postal questionnaires--a systematic review of randomised trials in health research.

BACKGROUND: Postal self-completion questionnaires offer one of the least expensive modes of collecting patient based outcomes in health care research. The purpose of this review is to assess the efficacy of methods of increasing response to postal questionnaires in health care studies on patient populations. METHODS: The following databases were searched: Medline, Embase, CENTRAL, CDSR, PsycINFO, NRR and ZETOC. Reference lists of relevant reviews and relevant journals were hand searched. Inclusion criteria were randomised trials of strategies to improve questionnaire response in health care research on patient populations. Response rate was defined as the percentage of questionnaires returned after all follow-up efforts. Study quality was assessed by two independent reviewers. The Mantel-Haenszel method was used to calculate the pooled odds ratios. RESULTS: Thirteen studies reporting fifteen trials were included. Implementation of reminder letters and telephone contact had the most significant effect on response rates (odds ratio 3.7, 95% confidence interval 2.30 to 5.97 p = or <0.00001). Shorter questionnaires also improved response rates to a lesser degree (odds ratio 1.4, 95% confidence interval 1.19 to 1.54). No evidence was found that incentives, re-ordering of questions or including an information brochure with the questionnaire confer any additional advantage. CONCLUSION: Implementing repeat mailing strategies and/or telephone reminders may improve response to postal questionnaires in health care research. Making the questionnaire shorter may also improve response rates. There is a lack of evidence to suggest that incentives are useful. In the context of health care research all strategies to improve response to postal questionnaires require further evaluation.

Correspondence as Topic↗

PubMed2006

Cerebral palsy life expectancy.

The life expectancy of people who have perinatally acquired cerebral palsy can be similar to that of the general population, or it can be reduced substantially. The most important factors that are associated with reduced survival are disabilities of motor, cognitive, or visual functions. Prematurity and low birth weight are associated with lower rates of disability, and better survival. A 2-year-old who has severe cerebral palsy has about a 40% chance of living to age 20, in contrast to a child who has mild cerebral palsy, for whom the chance is 99%. Cerebral palsy, respiratory diseases, epilepsy, and congenital malformation are the most commonly recorded causes of early death.

Birth Weight↗

PubMed2006

Long-term survival for a cohort of adults with cerebral palsy.

The aim of this study was to investigate long-term survival and examine causes of death in adult patients with cerebral palsy (CP). A 1940-1950 birth cohort based on paediatric case referral allows for long-term survival follow-up. Survival is analyzed by birth characteristics and severity of disability from age 20 years (and age 2y for a subset of the data). Survival outcome compared with that expected in the general population based on English life tables. The main cohort consisted of 341 individuals, with 193 males and 148 females. Conditional on surviving to age 20 years, almost 85% of the cohort survived to age 50 years (a comparable estimate for the general population is 96%). Very few deaths were attributed to CP for those people dying over 20 years of age. Females survived better than males. However, females faced a greater increase in risk relative to the general population than did males. We conclude that survival outlook is good though lower than in the general population. The relative risk of death compared with the UK population decreases with age, although it shows some indication of rising again after age 50 years. Many more deaths were caused by diseases of the respiratory system among those dying in their 20s and 30s than would be expected in the general population. Many fewer deaths than expected in this age group are caused by injuries and accidents. For those people who die in their 40s and 50s, an increase in deaths due to diseases of the circulatory system and neoplasms is observed. More deaths than expected in this age group are due to diseases of the nervous system.

Adolescent↗

PubMed2005

Regional variation in survival of people with cerebral palsy in the United Kingdom.

OBJECTIVES: Regional variation in survival of people who have cerebral palsy (CP) has been observed but not previously investigated in detail. In addition to true differences, variations in the methods and definitions used, completeness of ascertainment, and the role of potential confounding factors all have been proposed as possible explanations for these observed variations. Our aim was to assess the regional differences in survival of young people with CP and the effect on survival of socioeconomic differences after adjustment for variations in level of impairment and birth characteristics. METHODS: Survival patterns for young people with CP were calculated using information from a collaborative database. This database consisted of registrations of children who were born with CP in 5 geographically defined areas in the United Kingdom between 1980 and 1996. Notification of subsequent deaths was provided by the relevant births and death register. We consider the effects of birth characteristics, socioeconomic status, and severity of CP on survival. RESULTS: There were 325 deaths among the 4007 cases of CP identified. The proportion of affected children who survived to 20 years of age ranged from 85% (Mersey-side and Cheshire, male individuals) to 94% (North of England, male individuals). Multivariate modeling showed that the severity of impairment had the biggest impact on survival and that additional contributions were made by birth weight and socioeconomic status but that after such adjustments regional differences were no longer significant. CONCLUSIONS: The number and the severity of impairments are the best predictors of survival in young people with CP. After adjustment for the number of impairments, children who were born in affluent areas and had a low birth weight have an increased risk for death over those who were born with a normal birth weight. The same does not hold, however, for those who were born in deprived areas.

Adolescent↗

PubMed2004

Multiple birth and cerebral palsy in Europe: a multicenter study.

BACKGROUND: A European multicenter study (Surveillance of Cerebral Palsy in Europe, SCPE) was used to describe changes over time in multiple birth rates and cerebral palsy (CP) rates among multiple born infants, to compare CP rates and clinical types between multiples and singletons, and to analyse the influence of birth order in twins. METHODS: Data were collected from 12 European population-based CP registers on 6613 children born in 1975-90, as well as demographic data. RESULTS: The rate of multiple birth in the populations increased from 1.9% in 1980 to 2.4% in 1990, and the proportion of multiples among CP infants increased from 4.6% in 1976 to 10% in 1990. Multiples have a four times higher rate of CP than singletons [7.6 vs. 1.8 per 1000 live births, relative risk (RR) 4.36; 95% confidence interval (CI) 3.76-4.97] overall. The risk is marginally higher in multiples with birthweight > 2500 g (RR 1.60; 95% CI 0.95-2.28) and born at term (RR 1.65; 95% CI 0.91-2.40), and there is no difference in the risk for the low-birthweight and preterm groups. Correcting for differences in gestational age and birthweight, the clinical type of CP was the same in multiples and singletons. Twin CP infants are more often second than first born (56% vs. 44%, p < 0.05). CONCLUSIONS: Multiple born infants have a four times higher risk of developing cerebral palsy than singletons, mainly related to the higher risk of preterm birth in multiples. As the rate of multiples doubled through the 1980s, cerebral palsy cases in multiples increased in the same period.

Birth Weight↗

PubMed2002

Aggregate data meta-analysis with time-to-event outcomes.

In a meta-analysis of randomized controlled trials with time-to-event outcomes, an aggregate data approach may be required for some or all included studies. Variation in the reporting of survival analyses in journals suggests that no single method for extracting the log(hazard ratio) estimate will suffice. Methods are described which improve upon a previously proposed method for estimating the log(HR) from survival curves. These methods extend to life-tables. In the situation where the treatment effect varies over time and the trials in the meta-analysis have different lengths of follow-up, heterogeneity may be evident. In order to assess whether the hazard ratio changes with time, several tests are proposed and compared. A cohort study comparing life expectancy of males and females with cerebral palsy and a systematic review of five trials comparing two anti-epileptic drugs, carbamazepine and sodium valproate, are used for illustration.

Anticonvulsants↗

PubMed2002

Statistical issues in the assessment of the evidence for an interaction between factors in epilepsy trials.

We examine the common clinical belief that there is an interaction between epilepsy type and the two standard anti-epileptic drugs, valproate and carbamazepine, using data from several randomized clinical trials. Epilepsy type is not always easy to define, and three possible reclassifications are investigated to see whether misclassification of epilepsy type within the trials has potentially masked such an interaction. Regression modelling is employed to investigate whether heterogeneity between trial results can be explained by patient factors. Our work suggests that uncertainty in epilepsy type classification should be recognized in future studies. We also generate the hypothesis that the interaction of drug effect with age may reflect the perceived interaction with epilepsy type. We suggest that in any context where misclassification is likely, it is worth considering the use of an explicit 'unclassified' group, and investigating whether additional covariates can answer the substantive question.

Adolescent↗

PubMed2002

Deprivation and stillbirth risk in rural and urban areas.

The objective of the study was to investigate whether stillbirth risk was higher, and the effect of deprivation on inequality in stillbirth risk more marked, in rural than in urban areas. We carried out a cohort study of all 280 757 singleton births to mothers domiciled in Cumbria, north-west England, 1950-92. After allowing for individual social class and community deprivation, the risk of stillbirth was lower outside urban centres both during 1950-65 (OR = 0.91, 95% CI 0.84, 1.00) and during 1966-92 (OR = 0.82, 95% CI 0.73, 0.92). In earlier years, unsupported mothers in rural areas and mothers living in remote areas were particularly at risk. Urban/rural differences in risk were not explained by individual social class, community deprivation or overcrowding and have persisted over a 40-year time period.

Cohort Studies↗

PubMed2002

Carbamazepine versus valproate monotherapy for epilepsy: a meta-analysis.

PURPOSE: To provide an overview of the evidence comparing carbamazepine (CBZ) and valproate (VPA) monotherapy for epilepsy, investigating whether existing data support the current practice of preferring CBZ for partial-onset and VPA for generalized-onset seizures. METHODS: We performed meta-analysis of randomized controlled trials by using individual patient data. Our strategy included searches of (a) Medline, 1966-2000; (b) The Cochrane Library 2000, issue 4; and (c) the pharmaceutical industry. Outcome measures were time to discontinuation of allocated treatment, time to 12-month remission, and time to first seizure after randomization. Results are expressed as hazard ratios (HRs; 95% CI), where HR>1 indicates that an event is more likely with VPA. A test for an interaction between treatment and seizure type (partial vs. generalized onset) also was undertaken. RESULTS: Data were available for 1,265 patients from five trials. Overall results (HR, 95% CI) were Time to treatment discontinuation, 0.97 (0.79-1.18); 12-Month remission, 0.87 (0.74-1.02); and First seizure, 1.09 (0.96-1.25), suggesting no overall difference for these outcomes. The test for an interaction between Treatment and Seizure type was significant for time to first seizure, but for no other outcome. The age distribution of adults classified as having generalized seizures indicated that significant numbers of patients may have had their seizures misclassified. CONCLUSIONS: We found some evidence to support the preference of CBZ for partial-onset seizures, but no evidence to support the preference of VPA for generalized-onset seizures. Confidence intervals are too wide to infer equivalence. Misclassification of patients may have confounded our results and has important implications for future trials.

Adolescent↗