Wherein lies the truth? Assessment of agreement between parent proxy and child respondents

How can we better evaluate paediatric progression of myopia and associated risk factors? Lessons from the COVID-19 pandemic: A systematic review

PURPOSE

During the COVID-19 pandemic, home-based and remote learning-particularly using electronic devices-was rapidly pushed out. Increased near-work, screen time exposure and lack of outdoor time are risk factors that contribute to childhood myopia, but it is difficult to adopt recommendations from prior publications as a consistent limitation in the literature is the heterogeneity of research methodology. This review seeks to systematically evaluate how observational studies published during the pandemic have quantified and measured risk factors and myopia in school-going children and adolescents.

METHODS

Three scientific databases (PubMed, CINAHL, Scopus) were systematically searched from March 2020 to April 2022. Findings from relevant studies were descriptively summarised in relation to the PICOS-based objective of the review.

RESULTS

The final sample of 13 studies included research from six countries and comprised 1 411 908 children and adolescents. The majority of studies (N = 10; 76.9%) used spherical equivalent refraction (SER) of -0.5 dioptres or lower as a common definition of myopia. Most studies (77.8%) measuring screen time exposure found it higher during COVID-19 compared to pre-COVID, but only one study used objective measurement of screen time. The average critical appraisal score of the sample was only 66.1%, with a considerable number of studies failing to identify and adjust for potential confounders.

CONCLUSION

Future studies should consider emergent objective and validated measures of risk factors, account for potential a priori confounders and covariates and ensure more representativeness in the sociodemographic makeup of their samples.

Utility of the Actiwatch Spectrum Plus for detecting the outdoor environment and physical activity in children

PURPOSE

To describe the performance of the Actiwatch Spectrum Plus (Philips, Respironics) for determining real world indoor and outdoor environments and physical activity in children.

METHODS

Children wore the device while performing 10 different activities, ranging from sedentary to vigorous physical-activity, and under different indoor and outdoor conditions. Repeated measures ANOVA was implemented via mixed effects modeling to determine illuminance (lux) and physical activity (counts per 15 s, CP15) across conditions. Receiver operator characteristics (ROC) analysis assessed the accuracy to detect indoor versus outdoor settings.

RESULTS

Illuminance was found to be statistically different across indoor (793 ± 348 lux) and outdoor (4,413 ± 518 lux) conditions (P<.0001), with excellent diagnostic accuracy to detect indoor versus outdoor settings (Area under the ROC Curve, AUC 0.94); 1088 lux was identified as the optimal threshold for outdoor illuminance (sensitivity: 93.0%; specificity: 85.0%). Using published activity ranges, we found that when children were sitting, 94% of the physical-activity readings were classified as sedentary or light. When children were walking, 88% of readings were classified as light, and when children were running, 77% of readings were classified as moderate or vigorous.

CONCLUSION

The Actiwatch Spectrum Plus performed well during real world activities in children, showing excellent diagnostic accuracy at 1088 lux as a threshold to detect indoor versus outdoor environments and in categorizing physical activity.

Objective measures of viewing behaviour in children during near tasks

CLINICAL RELEVANCE

Objective assessment of near viewing behaviours performed in a laboratory setting showed that children demonstrate differing viewing distances and angles based on the type of task. Findings will contribute to our understanding of how near work influences myopia.

BACKGROUND

Evidence suggests that near working distance and viewing breaks are associated with myopia. The purpose of this study was to use an objective, continuously measuring range finding device to examine these viewing behaviours in children.

METHODS

Viewing distance, number of breaks, and head and eye angles were assessed in 16 non-myopic and 19 myopic children (ages 13.38 ± 4.14 years) using the Clouclip, an objective rangefinder, during five 15-minute near tasks, including (a) passive reading and (b) active writing on printed material, (c) passive viewing and (d) active engagement on an iPad, and (e) active engagement on a cell phone. Height and Harmon distance were measured. Viewing behaviours were analysed by task, refractive error group, and gender.

RESULTS

Mean viewing distances significantly differed by task (P < 0.001) and were highly correlated with children's Harmon distance and height for all near tasks (P < 0.05), except for the active printed task (P > 0.05). Viewing distances did not differ by gender or refractive error group. During each task, mean number of viewing breaks was 2.6 ± 4.1 and did not vary between task (P = 0.92) or refractive error group (P = 0.65). Head declination and total viewing angle varied by type of near task (P < 0.001 for both).

CONCLUSION

Children demonstrated differing viewing distances and viewing angles based on the type of near task they were performing. Viewing behaviours did not vary between myopic and non-myopic children. Findings will contribute to a better understanding of how near viewing behaviours can be quantified objectively and relationships with myopia.

A systematic review of near work and myopia: measurement, relationships, mechanisms and clinical corollaries

After decades of investigation, the role of near work in myopia remains unresolved, with some studies reporting no relationship and others finding the opposite. This systematic review is intended to summarize classic and recent literature investigating near work and the onset and progression of myopia, potential mechanisms and pertinent clinical recommendations. The impact of electronic device use is considered. PubMed and Medline were used to find peer-reviewed cross-sectional and longitudinal studies related to near work and myopia from 1980 to July 2020 using the PRISMA checklist. Studies were chosen using the Joanna Briggs Institute checklist, with a focus on studies with a sample size greater than 50. Studies were independently evaluated; conclusions were drawn per these evaluations. Numerous cross-sectional studies found increased odds ratio of myopia with increased near work. While early longitudinal studies failed to find this relationship, more recent longitudinal studies have found a relationship between myopia and near work. Rather than daily duration of near work, interest has increased regarding absolute working distance and duration of continuous near viewing. Several reports have found that shorter working distances (<30 cm) and continuous near-work activity (>30 min) are risk factors for myopia onset and progression. Novel objective continuously measuring rangefinding devices have been developed to better address these questions. The literature is conflicting, likely due to the subjective and variable nature in which near work has been quantified and a paucity of longitudinal studies. We conclude that more precise objective measures of near viewing behaviour are necessary to make definitive conclusions regarding the relationship between myopia and near work. Focus should shift to utilizing objective and continuously measuring instruments to quantify near-work behaviours in children, followed longitudinally, to understand the complex factors related to near work. A better understanding of the roles of absolute working distance, temporal properties, viewing breaks and electronic device use on myopia development and progression will aid in the development of evidence-based clinical recommendations for behavioural modifications to prevent and slow myopia.

Objective Measures of Near Viewing and Light Exposure in Schoolchildren during COVID-19

SIGNIFICANCE

Wearable sensors provide the opportunity for continuous objective measurement of the visual environment with high resolution. Our findings show that absolute and temporal properties of near viewing and time outdoors vary between myopic and nonmyopic schoolchildren, which are important considerations when studying refractive error pathogenesis.

PURPOSE

Numerous behavioral factors, including near work, time outdoors, electronic device use, and sleep, have been linked to myopia. The purpose of this study was to assess behaviors using subjective and objective methods in myopic and nonmyopic schoolchildren in the United States.

METHODS

Forty children (aged 14.6 ± 0.4 years) simultaneously wore two sensors for 1 week, a Clouclip for objective measurement of near viewing and light exposure and an Actiwatch for objective measurement of activity and sleep. Parents completed an activity questionnaire for their child. Near-viewing distance, daily duration, short-duration (>1 minute) and long-duration (>30 minutes) near-viewing episodes, light exposure, time outdoors, electronic device use, and sleep duration were analyzed by refractive error group and day of the week.

RESULTS

Objectively measured daily near-viewing duration was 6.9 ± 0.3 hours. Myopes spent more time in near + intermediate viewing than nonmyopes (P = .008) and had higher diopter hours (P = .03). Short- and long-duration near-viewing episodes were similar between groups (P < .05 for both). Daily light exposure and time outdoors were significantly lower for myopes (P < .05 for both). Electronic device use (12.0 ± 0.7 hours per day) and sleep duration (8.2 ± 0.2 hours per night) were similar between groups (P > .05 for both).

CONCLUSIONS

Objective and subjective measures confirm that myopic and nonmyopic schoolchildren exhibit different behaviors. Combining wearable sensors with questionnaires provides a comprehensive description of children's visual environment to better understand factors that contribute to myopia.

Wearable Sensors for Measurement of Viewing Behavior, Light Exposure, and Sleep

The purpose of this study was to compare two wearable sensors to each other and to a questionnaire in an adult population. For one week, participants aged 29.2 ± 5.5 years (n = 25) simultaneously wore a Clouclip, a spectacle-mounted device that records viewing distance and illuminance, and an Actiwatch, a wrist-worn device that measures illuminance and activity. Participants maintained a daily log of activities and completed an activity questionnaire. Objective measures of time outdoors, near (10–< 60 cm) and intermediate (60–100 cm) viewing, and sleep duration were assessed with respect to the daily log and questionnaire. Findings showed that time outdoors per day from the questionnaire (3.2 ± 0.3 h) was significantly greater than the Clouclip (0.9 ± 0.8 h) and Actiwatch (0.7 ± 0.1 h, p < 0.001 for both). Illuminance from the Actiwatch was systematically lower than the Clouclip. Daily near viewing duration was similar between the questionnaire (5.7 ± 0.6 h) and Clouclip (6.1 ± 0.4 h, p = 0.76), while duration of intermediate viewing was significantly different between methods (p < 0.001). In conclusion, self-reported time outdoors and viewing behaviors were different than objective measures. The Actiwatch and Clouclip are valuable tools for studying temporal patterns of behavioral factors such as near work, light exposure, and sleep.

Objective Behavioral Measures in Children before, during, and after the COVID-19 Lockdown in Israel

Studies using questionnaires report that COVID-19 restrictions resulted in children spending significantly less time outdoors. This study used objective measures to assess the impact of pandemic-related restrictions on children’s behavior. A total of 19 healthy 8–12-year-old boys were observed before and during social restriction periods. Of these, 11 boys were reassessed after restrictions were lifted. For each session, Actiwatches were dispensed for measures of time outdoors, activity, and sleep. Changes overall and by school status were assessed using signed-rank test and Wilcoxon rank sum tests. During restrictions, children spent significantly less time outdoors (p = 0.001), were less active (p = 0.001), and spent less time engaged in moderate-to-vigorous physical activity (p = 0.004). Sleep duration was not significantly different between sessions (p > 0.99), but bedtime and wake time shifted to a later time during restrictions (p < 0.05 for both). Time outdoors and activity returned close to pre-pandemic levels after restrictions were lifted (p > 0.05 for both). Children’s behaviors significantly changed during the COVID-19 pandemic. The reduction in outdoor light exposure is of importance due to the role of light in the etiology of myopia and vitamin D production. The reduction in physical activity may have negative health effects in terms of obesity and depression, although further research is required to ascertain the long-term effects.

Validation of the Clouclip and utility in measuring viewing distance in adults

PURPOSE

To validate the Clouclip, a continuously measuring objective rangefinder, and examine viewing behaviours during various near tasks in non-myopic and myopic adults.

METHODS

In experiment 1, five Clouclip devices were utilised. An infrared camera was used to visualise and measure infrared beam size and angle. Repeatability for distance tracking was assessed from 5 to 120 cm in 5 cm increments. Accuracy of distance tracking was investigated for paper and iPad targets, spatial integration was calculated, effects of target tilt were determined and light measurements were compared to a lux meter. In experiment 2, viewing behaviour was assessed in 41 subjects (21 non-myopic, 20 myopic) during four 15-min near tasks; (1) passive reading of printed material, (2) active writing on printed material, (3) passive viewing on an electronic device and (4) active engagement on an electronic device. Working distance was compared between tasks and refractive error groups.

RESULTS

Clouclip distance tracking showed good repeatability, with a mean difference of 0.34 cm and limits of agreement of ±2.0 cm. Clouclip-measured and actual distances were highly correlated for paper and electronic targets from 5 to 120 cm, with mean differences and limits of agreement of 3.96 ± 13.78 cm and 4.48 ± 8.92 cm, respectively; variability increased for distances >100 cm. Tracking ability increased with larger target sizes; tracking was accurate when the target occupied 1.5%-20.3% of tracking beam area, depending on distance and with target tilt up to ±60 degrees. Clouclip- and lux meter-measured ambient illumination were highly correlated for a wide range of intensities (r = 0.96, p < 0.001), but with greater variability for intensities >20 000 lux. The Clouclip infrared beam was measured to have a diameter of 25.6 ± 2.2° and a downward angle of 10.3 ± 0.5°. For subject testing, viewing distance was significantly closer for active and passive printed tasks (29.5 ± 6.7 cm and 33.2 ± 8.8 cm, respectively) than for active and passive electronic tasks (35.4 ± 8.0 cm and 40.8 ± 10.4 cm, respectively), with no differences between refractive error groups (p = 0.88).

CONCLUSIONS

The Clouclip performed well in measuring near and intermediate distances and could distinguish between indoor (<1000 lux) and outdoor (>1000 lux) illumination. A closer working distance was observed for printed tasks compared to those on an iPad, with no difference in viewing distance between non-myopic and myopic adults.

Continuous Objective Assessment of Near Work

Evidence regarding the role of near work in myopia is conflicting. We developed the RangeLife, a device for continuous, objective measurement of working distance. Four devices were built, calibrated, and validated. Then, adult subjects wore the device on weekdays and weekend days, while simultaneously wearing an actigraph device for objective measurements of light exposure and activity. Subjects maintained an activity log and answered a visual activity questionnaire. RangeLife data were downloaded and binned into 0.10 m intervals. Objective diopter hours (dh), a weighted measure of near work, were calculated. Diopter hours for all subjects were significantly higher on weekdays (14.73 ± 4.67 dh) compared to weekends (11.90 ± 4.84 dh, p = 0.05). 94 ± 1.85% of near and intermediate viewing distances were recorded when the subjects were exposed to mesopic and indoor photopic light levels (<1000 lux), and 80.03 ± 2.11% during periods of sedentary physical activity (<320 counts per minute). Subjective reports of time viewing near and intermediate distances significantly overestimated objective measures (p = 0.002). The RangeLife was shown to provide reliable measures of viewing distance, and can be further utilized to understand potential influences of viewing behaviors on refractive error.

Agreement between parent and child report of physical activity, sedentary and dietary behaviours in 9-12-year-old children and associations with children's weight status

BACKGROUND

To date, population based surveys aimed at gaining insight in health related behaviour of children have often used either child self-reports or parent proxy reports. It remains unclear however, if surveys using different sources of information from either parents or children are comparable. In addition, (over)weight status of children can lead to under- and over reporting by parents and children as a result of social desirability bias. We aimed at gaining insight in the level of agreement between parents and child reports regarding aspects of certain dietary, physical activity and sedentary behaviours, and whether there are differences in agreement between parents and child reports in healthy-weight and overweight children.

METHODS

Weighted kappa was used to determine the level of agreement between child and parent reports on health-related behaviour in 1998 parent-child dyads. We also stratified for weight status of the children. Information on children's health related behaviours was obtained by parental and children's questionnaires, and children's height and weight were measured. Associations between children's weight status and children reporting less, reporting more and reporting the same amount of health behaviour as their parents were investigated with multinomial logistic regression analysis.

RESULTS

The Cohen's kappa coefficients ranged from almost perfect agreement for the variable means of transportation, fair for the variables breakfast consumption and frequency of outside play to slight for the variables duration of outside play, frequency and duration of TV/DVD viewing and family dinner. Overweight children were significantly more likely to report less breakfast consumption (OR = 2.6 (95% CI: 1.3 - 5.1)) and lower frequency of outside play than their parents (OR = 1.8 (95% CI: 1.1 - 2.9)).

CONCLUSION

There can be considerable disagreement between the health related behaviours of children as reported by parents or the children themselves. Based on the present study, it cannot be concluded whether parents' or children's reports are more accurate. For future studies, social desirability and recall bias would be best demonstrated in a validation study comparing child and parent self-reports with more objective measures of physical activity and food intake.

Design of a prospective study on mental health and quality of life of maltreated children (aged 5-16 years) after a report to an advice and reporting center on child abuse and neglect

BACKGROUND

Child maltreatment is recognized as a widespread problem with huge implications for mental health and quality of life. Studies have repeatedly shown that victims of child maltreatment report significantly more adverse life outcomes than non-victims. The main objective of the study is (1) to examine the mental health and quality of life of maltreated children over a 1.5 year period beginning shortly after a report has been filed with an Advies- en Meldpunt Kindermishandeling (AMK) (advice and reporting center on child abuse and neglect). Secondary objectives are: (2) to examine how relevant determinants influence the mental health and quality of life of maltreated children, and (3) to examine differences in mental health and quality of life outcomes when comparing families of Dutch origin with families originating from Morocco and Suriname.

METHODS/DESIGN

A prospective study will be performed, in which parent-child dyads will be followed over a 1.5 year period. Participants will be recruited shortly after the report to the AMK and they will be asked to complete a questionnaire four times, at baseline and every six months thereafter. Data will be analyzed using a longitudinal multi-level analysis.

DISCUSSION

The study is expected to yield evidence about the mental health and quality of life of maltreated children and about determinants that influence their mental health and quality of life outcomes. Strengths of this study are (1) the design which makes it possible to start examining outcomes shortly after or even during the actual maltreatment and to follow parent-child dyads for 1.5 years, and (2) asking children as informants about their own situation by making use of self-report questionnaires as much as possible. Limitations include the risks of selection bias and loss to follow-up during 1.5 years of data collection.

TRIAL REGISTRATION

NTR3674, funded by ZonMw, project 15700.2012.

Family-based behavioural intervention program for obese children: an observational study of child and parent lifestyle interpretations

Background

Family-based behavioural intervention programs (FBIPs) against childhood obesity have shown promising results, but the mediating mechanisms have not been identified. The aim of this study was to examine changes in obese childreńs lifestyle habits during a 2-year FBIP according to their own and parents’ reports, the concordance between these reports and the correlations to change in post-intervention z-BMI.

Methods

An observational study of 26 children (8.3–12.0 years) and their parents participating in a 2-year FBIP was performed. Weight and height were measured from baseline to 12 months after the end of the program. Eating habits and physical- and sedentary activity were reported separately by children and parents. Data were analysed with regard to concordance between parents’ and children’s reports and association between the lifestyle reports and change in z-BMI at the study endpoint using descriptive statistics and parametric and non-parametric tests.

Results

According to both children’s and parents’ reports, the level of physical activity among the children had increased after the intervention as well as the agreement between the informants’ reports. According to the children, eating habits had improved, while the parents’ reports showed an improvement only with regard to binge eating. The concordance between children and parents regarding eating habits was slight to fair also after the intervention. No statistically significant associations between changes in lifestyle reports and changes in z-BMI were observed.

Conclusions

Child and parent reports of physical activity were found to converge and display an improvement in a 2-year FBIP, while the reports on eating habits showed a more refractory pattern. Changes in concordance and agreement between children and parents reports did not correlate with weight reduction. Further methods development and studies of the processes during family-based interventions against childhood obesity are warranted.

Parents and school children reported symptoms and treatment of allergic disease differently

OBJECTIVE

To examine the difference between children and their parents in reporting symptoms and treatment of allergic diseases within a longitudinal birth cohort.

STUDY DESIGN AND SETTING

Information on symptoms and treatment of asthma, rhinitis, and eczema was obtained by questionnaire from 2,744 children (mean age: 12 years) and their parents. Differences between the responses were computed, and agreement assessed both absolutely and with kappa coefficient.

RESULTS

On 12 of the 15 questions, children's and parents' reports differed significantly. Asthma-related issues appeared significantly more prevalent in the children's reports, although kappa values were fair to very good. For symptoms of allergic rhinitis, the prevalence pattern varied, and kappa values were moderate to good. Parents reported a higher prevalence of eczema-related issues, but the children reported a significantly higher prevalence of eczema itself. Kappa values ranged from moderate to good.

CONCLUSION

Although reports of allergic symptoms and treatment by 12-year-old children and their parents were in moderate-to-good agreement, children reported more symptoms than their parents. Symptoms of allergic disease should be reported by children themselves, from the age of 11 years, whereas questions of prescribed pharmacological treatment could be answered either by the children or their parents.

Measuring psychological outcomes following pediatric intensive care unit hospitalization: psychometric analysis of the Children's Critical Illness Impact Scale

OBJECTIVE

Critically ill children are at risk for psychological sequelae following pediatric intensive care unit hospitalization. This article reports on the psychometric testing of the first self-report measure of psychological distress for 6-12-yr-old children post-pediatric intensive care unit hospitalization: The Children's Critical Illness Impact Scale. This 23-item scale takes approximately 15 mins for children to complete.

DESIGN

Psychometric testing based on Classic Test Theory and guidelines for health measurement scale development.

SETTING

The pediatric intensive care units of four Canadian pediatric hospitals and the ear, nose, and throat clinic of one participating hospital.

PATIENTS

A total of 172 children (pediatric intensive care unit group, n = 84; ear, nose, and throat group, n = 88) aged 6-12 yrs and their parents.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We assessed the factor structure, internal consistency, and test-retest reliability of the Children's Critical Illness Impact Scale and conducted contrasted group comparisons and convergent and concurrent validation testing. Fit indices and internal consistency were best for a three-factor solution, suggesting three dimensions of psychological distress: 1) worries about getting sick again, 2) feeling things have changed, and 3) feeling anxious and fearful about hospitalization. As expected, Children's Critical Illness Impact Scale scores were positively correlated with child anxiety and medical fear scores. The ear, nose, and throat group scores were higher than expected. Higher Children's Critical Illness Impact Scale scores in older children may reflect a better understanding of the situation and its complexity and meaning, and younger children's tendency to provide more positive self-evaluation.

CONCLUSIONS

The Children's Critical Illness Impact Scale is a promising new self-report measure of psychological distress with demonstrated reliability and validation testing in 6-12-yr-old children post-pediatric intensive care unit hospitalization. This new measure has potential to advance the evidence base for pediatric intensive care unit and post-pediatric intensive care unit health promotion interventions.

Completeness and utility of interview data from proxy respondents in prenatal care research in rural China

In household surveys, the use of data provided by relatives can increase response rates and generalisability of research findings. This study assessed the quality of data from relatives and the impact of the data source on the association between the use of prenatal care and pregnancy outcomes. Data for 3,673 new mothers and 293 proxy respondents were available from a house-hold survey in 2008-2009 in rural China. Analyses were performed using chi-square test, ANOVA, Kruskal-Wallis test, and logistic regression models. Differences in the studied variables were small, but proxy respondents were slightly more likely to have missing data than the new mothers. Differences and missing data were more common for the use of prenatal care and outcome variables (mode of delivery, place of delivery, birth weight, use of postnatal care, and gestational age at birth) than for the background characteristics of the participants. Husbands' reports were closer to the index reports than that of the other proxies. The associations between the exposures and outcomes were mostly similar between the proxy and index respondents. Relatives can be interviewed instead of women to study prenatal care without a substantial negative impact on study results. Studies using proxy respondents should stratify the analysis by type of respondents.

Do agreements between adolescent and parent reports on family socioeconomic status vary with household financial stress?

BACKGROUND

Many studies compared the degree of concordance between adolescents' and parents' reports on family socioeconomic status (SES). However, none of these studies analyzed whether the degree of concordance varies by different levels of household financial stress. This research examines whether the degree of concordance between adolescents' and parent reports for the three traditional SES measures (parental education, parental occupation and household income) varied with parent-reported household financial stress and relative standard of living.

METHODS

2,593 adolescents with a mean age of 13 years, and one of their corresponding parents from the Taiwan Longitudinal Youth Project conducted in 2000 were analyzed. Consistency of adolescents' and parents' reports on parental educational attainment, parental occupation and household income were examined by parent-reported household financial stress and relative standard of living.

RESULTS

Parent-reported SES variables are closely associated with family financial stress. For all levels of household financial stress, the degree of concordance between adolescent's and parent's reports are highest for parental education (κ ranging from 0.87 to 0.71) followed by parental occupation (κ ranging from 0.50 to 0.34) and household income (κ ranging from 0.43 to 0.31). Concordance for father's education and parental occupation decreases with higher parent-reported financial stress. This phenomenon was less significant for parent-reported relative standard of living.

CONCLUSIONS

Though the agreement between adolescents' and parents' reports on the three SES measures is generally judged to be good in most cases, using adolescents reports for family SES may still be biased if analysis is not stratified by family financial stress.

Life course sun exposure and risk of prostate cancer: population-based nested case-control study and meta-analysis

There is currently no means of primary prevention for prostate cancer. Increased exposure to ultraviolet-radiation may be protective, but the literature is inconclusive. We investigated associations of life course exposure to sunlight with prostate cancer. The study design was a UK-wide nested case-control study, based on 1,020 prostate specific antigen-detected cases and 5,044 matched population controls and a systematic review with meta-analysis. Men with olive/brown skin (OR = 1.47; 95% CI: 1.00 to 2.17), men who burnt rarely/never (OR = 1.11; 0.95 to 1.29) and men with the lowest levels of intense sun exposure in the 2 years prior to diagnosis (OR = 1.24; 1.03 to 1.50) had an increased prostate cancer risk. However, amongst men with prostate cancer, spending less time outside was associated with a reduced risk of advanced cancer (OR = 0.49; 0.27 to 0.89) and high Gleason grade (OR = 0.62; 0.43 to 0.91), and men who burnt rarely/never had a reduced risk of advanced cancer (OR = 0.71; 0.47 to 1.08). The meta-analysis provided weak evidence that men with the lowest (versus highest) sunlight exposure had an increased prostate cancer risk (4 studies, random-effects pooled relative risk = 1.13; 0.98 to 1.29) and higher advanced or fatal prostate cancer risk (6 studies, random-effects pooled relative risk = 1.14; 0.98 to 1.33). Our data and meta-analyses provide limited support for the hypothesis that increased exposure to sunlight may reduce prostate cancer risk. The findings warrant further investigation because of their implications for vitamin D chemoprevention trials.

Health-related quality of life after prolonged pediatric intensive care unit stay

OBJECTIVE

To investigate the long-term health-related quality of life (HRQOL) outcomes for patients requiring at least 28 days of pediatric intensive care.

DESIGN

Retrospective cohort and prospective follow-up study.

SETTING

A 21-bed pediatric intensive care unit (PICU) in a university-affiliated, tertiary referral pediatric hospital.

PATIENTS

One hundred ninety-three patients who spent 28 days or longer in the PICU between January 1, 1997 and December 31, 2004.

INTERVENTIONS

Quality of life was measured using the Pediatric Quality of Life Inventory (Peds QL 4.0) parent-proxy version at 2 to 10 yrs after discharge. The PedsQL 4.0 is a modular measure of HRQOL, which is reliable in children aged 2 to 18 yrs. It generates a total score and physical, emotional, social, school, and psychosocial subscores.

MEASUREMENTS AND MAIN RESULTS

Of the 193 patients, 41 died during their PICU admission and 27 died between PICU discharge and follow-up. Quality of life questionnaires were posted to parents of 108 of the 125 survivors and 70 were returned completed. Forty children (57.1%) had scores indicating a normal quality of life, whereas 30 (42.9%) had scores indicating impaired HRQOL. Of these, 14 (20%) had scores indicating poor quality of life with ongoing disabling health problems requiring hospitalization or the equivalent.

CONCLUSIONS

Our results indicate that, while long PICU stay is associated with significant mortality, the long-term HRQOL is normal for the majority of surviving children.

The Queensland Study of Melanoma: environmental and genetic associations (Q-MEGA); study design, baseline characteristics, and repeatability of phenotype and sun exposure measures

Cutaneous malignant melanoma (CMM) is a major health issue in Queensland, Australia, which has the world's highest incidence. Recent molecular and epidemiologic studies suggest that CMM arises through multiple etiological pathways involving gene-environment interactions. Understanding the potential mechanisms leading to CMM requires larger studies than those previously conducted. This article describes the design and baseline characteristics of Q-MEGA, the Queensland Study of Melanoma: Environmental and Genetic Associations, which followed up 4 population-based samples of CMM patients in Queensland, including children, adolescents, men aged over 50, and a large sample of adult cases and their families, including twins. Q-MEGA aims to investigate the roles of genetic and environmental factors, and their interaction, in the etiology of melanoma. Three thousand, four hundred and seventy-one participants took part in the follow-up study and were administered a computer-assisted telephone interview in 2002-2005. Updated data on environmental and phenotypic risk factors, and 2777 blood samples were collected from interviewed participants as well as a subset of relatives. This study provides a large and well-described population-based sample of CMM cases with follow-up data. Characteristics of the cases and repeatability of sun exposure and phenotype measures between the baseline and the follow-up surveys, from 6 to 17 years later, are also described.

Administration of the Autism Behavior Checklist: agreement between parents and professionals' observations in two intervention contexts

OBJECTIVE: To determine the agreement between responses on the Autism Behavior Checklist by mothers and healthcare professionals. METHOD: Twenty-three mothers of children from the autism spectrum (DSM-IV-TR, 2002) were interviewed. The children were part of an educational program of the Autistic Friends Association-SP. The healthcare professionals in charge of the children at the institution filled out a questionnaire regarding the method for observing behavior. For comparison purposes, an additional 15 mothers of children from the autism spectrum were interviewed at the speech therapy clinic of Universidade Federal de São Paulo, and the speech therapists responsible for the children filled out the questionnaire on the observation method. The Kappa index was employed to obtain the frequency of agreement between mothers and healthcare professionals' observations on the overall Autism Behavior Checklist, as well as its individual components. The Student's t-test was used to assess differences or similarities between the Kappa results. RESULTS: The agreement index was low for the total score, with a statistically significant difference between both groups (p < 0.001). Agreement was also low for each Autism Behavior Checklist components, but there was greater agreement in the group treated at the public service in the Language, Body and Use of Objects components (p < 0.001). CONCLUSION: There was disagreement between the observations in both intervention contexts, but agreement was better at the public service than at Autistic Friends Association.

How do proxy responses and proxy-assisted responses differ from what Medicare beneficiaries might have reported about their health care?

OBJECTIVE

Assess proxy respondent effects on health care evaluations by Medicare beneficiaries.

DATA SOURCE

110,215 respondents from the nationally representative 2001 CAHPS((R)) Medicare Fee-for-Service Survey.

STUDY DESIGN/DATA COLLECTION/EXTRACTION METHODS

We compare the effects of both proxy respondents and proxy assistance (reading, writing, or translating) on 23 "objective" report items and four "subjective" global measures of health care experiences using propensity-score-weighted regression. We assess whether proxy effects differ among spouses, other relatives, or nonrelatives.

PRINCIPAL FINDINGS

Proxy respondents provide less positive evaluations of beneficiary health care experiences than otherwise similar self-reporting beneficiaries for more subjective global ratings (average effect of 0.21 standard deviations); differences are smaller for relatively objective and specific report items. Proxy assistance differences are similar, but about half as large. Reports from spouse proxy respondents are more positive than those from other proxies and are similar to what would have been reported by the beneficiaries themselves. Standard regression techniques may overestimate proxy effects in this instance.

CONCLUSIONS

One should treat proxy responses to subjective ratings cautiously. Even seemingly innocuous reading, writing, and translation by proxies may influence answers. Spouses may be accurate proxies for the elderly in evaluations of health care.

Oral health-related quality of life in children: part III. Is there agreement between parents in rating their children's oral health-related quality of life? A systematic review

OBJECTIVE

One issue that receives a great deal of attention is the comparison between measurement of children's oral health-related quality of life (OHRQoL) reports with those of their parents. However, the extent to which parents understand the effects of ill-health on their children's lives remains unanswered. The purpose of this systematic review was to identify the literature on the nature, extent and the pattern of agreement/disagreement between parent and child reports about child OHRQoL and assess the association between them.

MATERIALS AND METHODS

The literature was searched using MEDLINE, ISI, Lilacs and Scielo, from January 1985 to March 2007. The selected studies used well-validated instruments and provided children's and parent's perceptions of child OHRQoL.

RESULTS

A total of 87 articles were retrieved and five were selected for the review, which showed that children and parents do not necessarily share similar views about child OHRQoL. Some parents may have limited knowledge about their children's OHRQoL, particularly the impact on social and emotional well-being.

CONCLUSIONS

Valid and reliable information can be obtained from parents and children using appropriate questionnaire techniques. Although the parents' reports may be incomplete due to lack of knowledge about certain experiences, they still provide useful information.

Similar asthma prevalence estimates obtained from preadolescent and parent survey responses

OBJECTIVE

We compared agreement between child and parent responses to questions assessing prevalence of asthma and other severe respiratory symptoms.

STUDY DESIGN AND SETTING

Fifth-grade children enrolled in public schools and their parents separately completed a health survey, which included respiratory symptom questions from the International Study of Asthma and Allergies in Childhood (ISAAC). Agreement on respiratory symptom questions was assessed with Cohen's Kappa coefficient. Asthma prevalence estimates based on responses to several questions were also compared using child and parent data. The analysis was based on a study sample size of 230 matched parent and child questionnaires.

RESULTS

High levels of agreement (Kappa: 0.76 and 0.79) between child and parent responses were observed for current and lifetime asthma, and similar asthma prevalence estimates were obtained from child and parent response data. Five of the questions on potentially severe respiratory symptoms had low to fair levels of agreement (Kappa: -0.01 to 0.38), resulting in statistically significantly different prevalence estimates in three of the five symptoms.

CONCLUSIONS

Separate parent and child responses to a series of respiratory symptom and asthma questions yielded similar estimates for asthma prevalence but different estimates for the prevalence of several severe respiratory symptoms.

Agreement between teenager and caregiver responses to questions about teenager's asthma

It is unknown if teenagers and caregivers give similar responses when interviewed about the teen's asthma. We analyzed data for 63 urban African-American teen-caregiver pairs. Caregivers underestimated teen smoking by 30%, gave lower estimates for teen exposure to passive smoke, and disagreed with teens on controller medication usage. Teen-caregiver responses were not significantly different for estimates of symptom-days, activity limitations, or nights awakened; nor were they significantly different for report of emergency department visits or hospitalizations. Agreement was weak for perceived asthma control and severity. Teen-caregiver agreement on asthma depends on the type of information being sought.

Concordância de informações de adolescentes e suas mães em inquérito de saúde

OBJETIVO: Estimar o grau de concordância entre informações obtidas de trabalhadores adolescentes e suas mães em inquérito de saúde. MÉTODOS: Os dados provêm de inquérito populacional, de base domiciliar, conduzido com amostra aleatória de superfície de residentes da área urbana de Salvador, capital do Estado da Bahia. A amostra compõe-se de 82 pares de adolescentes trabalhadores de 10 a 14 anos de idade e suas mães. Após entrevista com os adolescentes, numa outra visita, suas mães foram convidadas a responder um questionário similar por um entrevistador cego. Sintomas respiratórios, depressivos, alterações do padrão do sono e problemas na vizinhança e na escola foram as variáveis analisadas. O grau de concordância foi estimado com proporções de acordo e Índice Kappa. RESULTADOS: Estimativas de acordo foram, em geral, baixas, com as mães fornecendo mais freqüentemente respostas positivas que os adolescentes, determinando vieses negativos, ou seja, estimativas menores, caso os resultados se baseassem no informante. A confiabilidade foi mais elevada entre os meninos em comparação com as meninas, para todas variáveis exceto para alterações do padrão de sono. Para sintomas depressivos, o nível de escolaridade da mãe se associou negativamente com o grau de concordância. CONCLUSÕES: Informações obtidas de adolescentes diferem das obtidas de suas mães. Baixas concordâncias não equivalem a um problema de validade, que deverá ser avaliada em estudos futuros para essa população.

Student–parent agreement in self-reported sun behaviors

OBJECTIVE

We sought to describe agreement between parent proxy and student self-reported sun behaviors and sun protective practices in adolescents aged 10 to 14 years.

METHODS

We conducted a cross-sectional pilot study of students (n = 52) from two classrooms, grades 6 and 7, at a school system in Framingham, Mass. Data were collected using self-administered questionnaires. Students were asked to report their sun behaviors and sun protective practices. Proxy measures were obtained by asking parents to report sun behaviors and practices of their children. Agreement was measured using weighted kappa analysis for ordinal data. Mean differences (95% confidence intervals) were calculated.

RESULTS

The response rate for student/proxy pairs was 96% (n = 50). Agreement between student and proxy was good for skin color, sunscreen use, number of sunburns in the past summer, and application of sunscreen while in other outdoor places (range kappa = 0.52-0.73). Lowest agreement was found for questions relating to wearing a shirt, wearing a hat, sitting in the shade, and frequency of parental sunscreen application to the students' backs (range kappa = 0.08-0.28). Mean differences in responses between student and proxy respondents were relatively small ranging from -0.39 to +0.25.

CONCLUSIONS

The lack of a gold standard in the assessment of sun exposure and related sun protective practices limits the ability to validate these exposure measures in skin cancer studies. The assessment of sun exposure behaviors is especially problematic when relying on a child's ability to accurately recall these exposures. Parent proxy measures are often used as surrogate measures and for validation purposes. We found low to moderate student/proxy agreement in this pilot study suggesting that adolescents can effectively recall their recent sun behaviors and protective practices when compared with parent proxy measures.

Reliability of sport fish consumption in the New York State Angler cohort study

This paper examines the reliability of sport fish consumption data from the New York State Angler Cohort Study (NYSACS). NYSACS is a prospective cohort study conducted among New York State registered sportsmen and fishermen. Sport fish consumption information for New York State waters including the Great Lakes between June 1990 and June 1991 were collected through self-administered questionnaires, Spouses of male anglers were asked to provide their husbands' fish consumption during the same time period. A short telephone interview after the cohort was ascertained was also conducted among about 100 study participants for the purpose of quality control. Percentage agreement, kappa, and weighted kappa were calculated to evaluate the reliability of the interview using spousal data and reinterview data. Overall, for the total fish consumption between June 1990 and June 1991, percentage agreement, kappa, and weighted kappa between spousal data and primary response were 67.28%, 0.5087, and 0.6157, respectively. For reinterview data, weighted kappa ranged from 0.4510 to 0.5285 for season-specific analysis and kappa ranged from 0.4615 to 0.7006 for fish species-specific analysis. Spouses may be a good source of proxy data for fish consumption. The reliability of sport fish consumption data for the NYSACS study is acceptable, suggesting that the food frequency measuring methods employed are a viable approach to obtain retrospective sport fish consumption data from sportsmen and subsistence anglers.

The quality of life for cancer children (QOLCC) for Taiwanese children with cancer (part II): feasibility, cross-informants variance and clinical validity

The quality of life in childhood cancer (QOLCC) is a research instrument that has been developed to assess the quality of life for children and adolescents who suffer from cancer in Taiwan. The current paper is the second of a two-part series of research reports. Part I is reported in this journal (Yeh et al., 2003). Part II describes the range of measurement, concordance of cross-informants reports, and clinical validity of Taiwanese pediatric cancer children (7-12 years) and adolescents (13-18 years) and their parents/caregivers. Due to the cognitive ability of children and adolescents, data were analyzed for children and adolescent separately. The validity of cross-referenced information between parent and child forms was subsequently examined using Pearson product correlation. The feasibility (percentage of missing values per item) and range of measurement [percentage of minimum (floor effect) and maximum (ceiling effect) possible scores] was calculated for the five QOLCC and the total scale score. The findings of medium to high correlation of the patient/parent responses strongly imply that relevant information might be obtainable through parents when children are unable or unwilling to complete the assessment instrument. Feasibility for the QOLCC was very good.

Can schoolchildren provide valid answers about their respiratory health experiences in questionnaires? Implications for epidemiological studies

To evaluate the relative validity of information on children's respiratory experience given by different informants, we examined and compared the relationship between low ventilatory function (defined as more than 1 standard deviation below the corresponding mean) and schoolchildren's respiratory symptoms or illnesses reported separately by the children and their parents, using a standard respiratory questionnaire. A total of 1,963 children aged 8-12 years from 12 primary schools in three districts of Hong Kong provided parent-completed and self-completed questionnaires, as well as acceptable spirometric measurements. Prevalence of low forced expiratory volume ratio (FEV1/FVC) and low forced expiratory flow rate between 25-75% of FVC (FEF25-75) were higher among those with either parent or child-reported symptoms/illnesses. Child-reported cough and phlegm performed better than the corresponding parent-reported symptoms in predicting low FEV1/FVC. The contrary was true for wheezing and bronchitis. For low FEF25-75, parent-reported wheezing, asthma, and bronchitis performed better, while the opposite was true for cough. Subgroup analysis by age showed that for older children (age 10 or above), child-reported symptoms/illnesses performed better in general in the prediction of low FEV1/FVC. On the other hand, parent-reported symptoms/illnesses seemed to have an advantage over child-reported ones in predicting low FEF25-75. Subgroup analysis by sex did not reveal any clear pattern. Overall, there was little difference between respiratory illness experiences reported by schoolchildren and their parents in terms of their associations with low ventilatory function. In a population-based study in which schoolchildren are subjects, it would be appropriate for respiratory questionnaires to be administered to the children themselves, especially if they have reached age 10. By doing so, higher response rates, and perhaps also better yields of correct information, may be obtained.

Measuring parental perceptions of child oral health-related quality of life

OBJECTIVES

The aim of this study was to develop and evaluate the P-CPQ, a measure of parental/caregiver perceptions of the oral health-related quality of life of children. This forms one component of the Child Oral Health Quality of Life Questionnaire (COHQOL).

METHODS

An item pool was developed through a review of existing child health questionnaires and interviews with parents/caregivers of children with pedodontic, orthodontic, and orofacial conditions. The resulting 47 items were used in a study in which 208 parents/caregivers provided data on their frequency and importance. The 31 items rated the most frequent and important were selected for the final questionnaire (P-CPQ). The P-CPQ validity and reliability were assessed by a new sample of 231 parents, 79 of whom completed two copies for the assessment of test-retest reliability.

RESULTS

The P-CPQ discriminated among the three clinical groups included in the expected direction. Within-group analyses using clinical data provided some evidence that scores were associated with the severity of the condition. The P-CPQ also showed good construct validity. It had excellent internal consistency reliability with a Cronbach's alpha of 0.94 and demonstrated perfect test-retest reliability (ICC=0.85).

CONCLUSION

The study provides data to indicate that the P-CPQ is valid and reliable.

Reliability of data from next-of-kin: results from a case-control study of occupational and lifestyle risk factors for cancer

BACKGROUND

Use of surrogate responders often needs to be considered in case-control studies with a high case fatality.

METHODS

Agreement between 98 colon cancer patients and their closest relative was expressed as a percentage of the exact agreement and by Kappa coefficients and intra-class correlation coefficients.

RESULTS

The percentage of "don't know" answers was higher for surrogates than for index cases and the highest percentage was seen for questions on early events like childhood diseases. Agreement was best for responses to dichotomous questions on smoking and for prevalent or chronic diseases like diabetes or psoriasis, and lower (54-64%) when a quantitative response of, e.g., smoking was requested. The next-of-kin reported fewer job periods than the study person, 4.5 and 2.8, respectively, and there was a higher agreement for the latest job held than for the longest held job. We found an overall agreement between 91% and 100% for responses to ever having worked in a specific type of industry or occupation.

CONCLUSIONS

Use of next-of-kin data will often be a better alternative than excluding severely ill or deceased cases, if the exposure under study correlates with disease progression.

The functional outcome and quality of life of children after admission to an intensive care unit

OBJECTIVE

To evaluate the long-term outcome of children following admission to a paediatric intensive care unit.

DESIGN

Prospective, long-term follow-up study.

SETTING

Sixteen-bed multi-disciplinary paediatric intensive care unit in a free-standing, university, tertiary, teaching hospital.

PATIENTS

All children consecutively admitted to the paediatric intensive care unit from 1(st) January, 1995, to 31(st) December, 1995.

INTERVENTIONS

Outcome was evaluated, by telephone interview, at a median of 3.5 years (range 2.3-6 years) after admission to the intensive care unit using a modification of the Glasgow Outcome Score (GOS) to assess functional outcome and the Health State Utility Index (Mark 1) to assess quality of life.

MEASUREMENTS AND MAIN RESULTS

Of the children admitted to the intensive care unit, 83.8% were alive at the time of follow-up. While 10.3% of the survivors had an unfavourable outcome and were likely to live dependent on care, 89.7% had a favourable outcome and were likely to lead an independent existence. Although 16.4% had an unfavourable quality of life, 83.6% of the children survived with a favourable quality of life. At the time of follow-up, 16.2% of the children were dead: 49% died in the intensive care unit, 5% died in hospital and 46% died after discharge from hospital.

CONCLUSIONS

The majority of children admitted to a paediatric intensive care unit survive with an excellent functional outcome and quality of life. Long-term outcome assessment provides a basis for observing trends in outcome over time within the same institution.

Levels of agreement between parents' and children's reports of near work

PURPOSE

To assess whether parents and children report the same information regarding children's near vision activities when given similar questionnaires.

METHODS

Data from questionnaires administered to 406 children and their parents were analyzed to evaluate the agreement between parent and child reports. The questionnaires were completed during the 1994 testing of the Orinda Longitudinal Study of Myopia. Each child and parent was asked to categorize how often the child reads for pleasure. In addition, each subject was asked to estimate how many hours per week were spent in each of five visual activities. The weighted kappa statistic, paired t-tests, and polytomous logistic regression were used for analyses.

RESULTS

A weighted kappa = 0.42 (moderate agreement) was found in the comparison of child-reported vs. parent-reported classification of reading. Agreement between parent- and child-reported number of hours spent doing homework (0.21), reading for pleasure (0.31), watching television (0.31), playing video games (0.31), and engaging in sports/outdoor activities (0.26) was fair for each activity.

CONCLUSIONS

Although the results indicate fair to moderate levels of agreement, better methods of reporting near-work activities are needed for future myopia research.

Physical activity assessment in children and adolescents

Chronic disease risk factors, including a sedentary lifestyle, may be present even in young children, suggesting that early prevention programmes may be critical to reducing the rates of chronic disease. Accurate assessment of physical activity in children is necessary to identify current levels of activity and to assess the effectiveness of intervention programmes designed to increase physical activity. This article summarises the strengths and limitations of the methods used to evaluate physical activity in children and adolescents. MEDLINE searches and journal article citations were used to locate 59 articles that validated physical activity measurement methods in children and adolescents. Only those methods that were validated against a more stringent measure were included in the review. Based on the definition of physical activity as any bodily movement resulting in energy expenditure (EE), direct observation of the individual's movement should be used as the gold standard for physical activity research. The doubly labelled water technique and indirect calorimetry can also be considered criterion measures for physical activity research, because they measure EE, a physiologic consequence closely associated with physical activity. Devices such as heart rate monitors, pedometers and accelerometers have become increasingly popular as measurement tools for physical activity. These devices reduce the subjectivity inherent in survey methods and can be used with large groups of individuals. Heart rate monitoring is sufficiently valid to use in creating broad physical activity categories (e.g. highly active, somewhat active, sedentary) but lacks the specificity needed to estimate physical activity in individuals. Laboratory and field validations of pedometers and accelerometers yield relatively high correlations using oxygen consumption (r = 0.62 to 0.93) or direct observation (r = 0.80 to 0.97) as criterion measures, although, they may not be able to capture all physical activity. Physical activity has traditionally been measured with surveys and recall instruments. These techniques must be used cautiously in a paediatric population that has difficulty recalling such information. Still, some studies have reported 73.4% to 86.3% agreement between these instruments and direct observation. Future investigations of physical activity instruments should validate the novel instrument against a higher standard. Additional studies are needed to investigate the possibility of improving the accuracy of measurement by combining 2 or more techniques. The accurate measurement of physical activity is critical for determining current levels of physical activity, monitoring compliance with physical activity guidelines, understanding the dose-response relationship between physical activity and health and determining the effectiveness of intervention programmes designed to improve physical activity.

Measuring health status using the Health Utilities Index: agreement between raters and between modalities of administration

The aim of this study was to evaluate interrater and intermodality agreement in assessing health status using the Health Utilities Index. A random sample from a Dutch cohort of 14-year-old Very Low Birth Weight children and their parents were invited to participate in a face-to-face (n = 150) or telephone (n = 150) interview. All 300 participants were also sent a questionnaire by mail. Response rate was 68%. Interrater and intermodality agreement were high for the physical HUI3 attributes and poor for the psychological attributes. Children and parents reported more dysfunction in the psychological attributes when interviewed than when completing the mailed questionnaire. High agreement on the physical attributes may have resulted from the fact that hardly any dysfunction was reported in these attributes, and poor agreement in the psychological attributes may have been a result of the fact that in these attributes much more dysfunction was reported. In measuring children's health status using the HUI3, the results and their interpretation vary with the source of information and the modality of administration. For maximum comparability between studies, written self-report questionnaires seem the preferred option.

Development and psychometric evaluation of the TAPQOL: a health-related quality of life instrument for 1-5-year-old children

The 43-item TNO-AZL Preschool Children Quality of Life (TAPQOL) questionnaire was developed to meet the need for a reliable and valid instrument for measuring parent's perceptions of health-related quality of life (HRQoL) in preschool children. HRQoL was defined as health status in 12 domains weighted by the impact of the health status problems on well-being. The aim of this study was to evaluate the psychometric performance of the TAPQOL. A sample of 121 parents of preterm children completed the TAPQOL questionnaire (response rate 88%) as well as 362 parents of children from the general population (response rate 60%). On the base of Cronbach's alpha, item-rest correlation, and principal component analysis, the TAPQOL scales were constructed from the data for the preterm children sample. The psychometric performance of these scales was evaluated for both the preterm children sample and the general population sample. Cronbach's alpha ranged from 0.66 to 0.88 for the preterm children sample and from 0.43 to 0.84 for the general population sample. The unidimensionality of the separate scales was confirmed by principal component analysis for both the preterm children sample and the general population sample. Spearman's correlation coefficients between scales were, on average, low. T-tests showed that the very preterm children, the children with chronic diseases, the less healthy and the less happy children had lower mean scores on the TAPQOL scales than healthy children, indicating a worse quality of life. This study shows that the TAPQOL is a reliable and valid parent's perception of HRQoL in preschool children. More research is needed to evaluate the psychometric performance of the TAPQOL in different clinical populations.

The effect of collapsing multinomial data when assessing agreement

BACKGROUND

In epidemiological studies researchers often depend on proxies to obtain information when primary subjects are unavailable. However, relatively few studies have performed formal statistical inference to assess agreement among proxy informants and primary study subjects. In this paper, we consider inference procedures for studies of interobserver agreement characterized by two raters and three or more outcome categories. Of particular interest is the consequence of dichotomizing such data on the expected confidence interval width for the kappa coefficient. The effect of dichotomization on sample size requirements for testing hypotheses concerning kappa is also evaluated.

METHODS

Simulation studies were used to compare coverage levels and widths for constructing confidence intervals. Sample size requirements were compared for multinomial and dichotomous data. We illustrate our results using a published data set on drinking habits that assesses agreement among primary and proxy respondents.

RESULTS

Our results show that when multinomial data are treated as dichotomous, not only do the expected confidence interval widths become greater, but the penalty in terms of larger sample size requirements for hypothesis testing can be severe.

CONCLUSION

We conclude that there are clear advantages in preserving multinomial data on the original scale rather than collapsing the data into a binary trait.

Measuring health-related quality of life in adolescents: agreement between raters and between methods of administration

The aim of this study was to evaluate the agreement between children and proxies as well as the agreement between methods of administration in assessing Health-Related Quality of Life (HRQoL) using the TNO AZL Children's Quality Of Life (TACQOL) questionnaire. A random sample from a Dutch cohort of 14-year-old very low birth weight children and their parents were invited to participate in a face-to-face (n = 150) or telephone interview (n = 150). Participants were also sent a questionnaire by mail. The response rate was 83%. Inter-rater and intermethod agreement were generally good in observable HRQoL domains, and moderate in less readily observable, and possibly less stable, domains such as moods, pain and physical symptoms, and social functioning. In measuring children's HRQoL using the TACQOL, the results and their interpretation are dependent on the source of information and the method of administration.

Agreement between older subjects and proxy informants on history of surgery and childbirth

OBJECTIVES

To assess the agreement between proxy informants' reports of history of surgery and childbirth and older index subjects' own recall.

DESIGN

Interrater reliability study.

SETTING

An outpatient family medicine clinic and a provincial electoral district in Montreal, Canada.

PARTICIPANTS

Eighty-two subjects aged 65 years and older without cognitive impairment, identified from clinic and community settings, and each index subject's proxy respondent.

MEASUREMENTS

Identical questionnaires were administered to index subjects and proxies.

RESULTS

Proxies failed to report 39% of non-childbirth surgeries reported by index subjects, but failed to report only 10% of childbirths. Female proxies were significantly less likely than male proxies to underreport non-childbirth surgeries after controlling for age of index subject and interval since surgery. Longer interval since surgery was significantly associated with greater underreporting, whereas age of the index subject and relationship between proxy and index subject were not. Agreement between proxies and index subjects on date of surgery was much higher for childbirths than for non-childbirth surgeries.

CONCLUSIONS

Our findings suggest that proxy respondents can provide reliable information on older women's history of childbirth but that use of proxy respondents for history of non-childbirth surgeries may result in substantial underreporting.

Agreement on responses to respiratory illnesses questionnaire

The prevalence of respiratory symptoms and illnesses among 2225 schoolchildren in Hong Kong was studied by questionnaires administered independently to them and their parents. The agreement was generally poor for respiratory symptoms. The disparity shows the need for cross validation of clinical information in history taking.