Childhood leukaemia and socioeconomic status: what is the evidence?

The objectives of this systematic review are to summarise the current literature on socioeconomic status (SES) and the risk of childhood leukaemia, to highlight methodological problems and formulate recommendations for future research. Starting from the systematic review of Poole et al. (Socioeconomic status and childhood leukaemia: a review. Int. J. Epidemiol. 2006;35(2):370-384.), an electronic literature search was performed covering August 2002-April 2008. It showed that (1) the results are heterogeneous, with no clear evidence to support a relation between SES and childhood leukaemia; (2) a number of factors, most importantly selection bias, might explain inconsistencies between studies; (3) there is some support for an association between SES at birth (rather than later in childhood) and childhood leukaemia and (4) if there are any associations, these are weak, limited to the most extreme SES groups (the 10-20% most or least deprived). This makes it unlikely that they would act as strong confounders in research addressing associations between other exposures and childhood leukaemia. Future research should minimise case and control selection bias, distinguish between different SES measures and leukaemia subtypes and consider timing of exposures and cancer outcomes.

Socioeconomic Status and Childhood Leukemia Incidence in Switzerland.

Socioeconomic status (SES) discrepancies exist for child and adult cancer morbidity and are a major public health concern. In this Swiss population-based matched case-control study on the etiology of childhood leukemia, we selected the cases from the Swiss Childhood Cancer Registry diagnosed since 1991 and the controls randomly from census. We assigned eight controls per case from the 1990 and 2000 census and matched them by the year of birth and gender. SES information for both cases and controls was obtained from census records by probabilistic record linkage. We investigated the association of SES with childhood leukemia in Switzerland, and explored whether it varied with different definitions of socioeconomic status (parental education, living condition, area-based SES), time period, and age. In conditional logistic regression analyses of 565 leukemia cases and 4433 controls, we found no consistent evidence for an association between SES and childhood leukemia. The odds ratio comparing the highest with the lowest SES category ranged from 0.95 (95% CI: 0.71-1.26; P trend = 0.73) for paternal education to 1.37 (1.00-1.89; P trend = 0.064) for maternal education. No effect modification was found for time period and age at diagnosis. Based on this population-based study, which avoided participation and reporting bias, we assume the potential association of socioeconomic status and childhood leukemia if existing to be small. This study did not find evidence that socioeconomic status, of Switzerland or comparable countries, is a relevant risk factor or strong confounder in etiological investigations on childhood leukemia.

Socioeconomic determinants of health related quality of life in childhood and adolescence: results from a European study

STUDY OBJECTIVE: The objective of this study was to investigate the impact of two different socioeconomic status (SES) measures on child and adolescent self reported health related quality of life (HRQoL). The European KIDSCREEN project aims at simultaneous developing, testing, and implementing a generic HRQoL instrument. DESIGN AND SETTING: The pilot version of the questionnaire was applied in school surveys to students from 8 to 18 years of age, as well as to their parents, together with such determinants of health status as two SES indicators, the parental educational status and the number of material goods in the family (FAS, family affluence scale). PARTICIPANTS: Students from seven European countries: 754 children (39.8%; mean: 9.8 years), and 1142 adolescents (60.2 %; mean: 14.1 years), as well as their respective parents. MAIN RESULTS: In children, a higher parental educational status was found to have a significant positive impact on the KIDSCREEN dimensions: physical wellbeing, psychological wellbeing, moods and emotions, bullying and perceived financial resources. Increased risk of low HRQoL was detected for adolescents in connection with their physical wellbeing. Family wealth plays a part for children's physical wellbeing, parent relations and home life, and perceived financial resources. For adolescents, family wealth furthermore predicts HRQoL on all KIDSCREEN dimensions. CONCLUSIONS: There is evidence to suggest that exposure to low parental educational status may result in a decreased HRQoL in childhood, whereas reduced access to material (and thereby social) resources may lead to a lower HRQoL especially in adolescence.

Socioeconomic disparities in childhood cancer survival in Switzerland.

In this study, we investigated whether childhood cancer survival in Switzerland is influenced by socioeconomic status (SES), and if disparities vary by type of cancer and definition of SES (parental education, living condition, area-based SES). Using Cox proportional hazards models, we analyzed 5-year cumulative mortality in all patients registered in the Swiss Childhood Cancer Registry diagnosed 1991-2006 below 16 years. Information on SES was extracted from the Swiss census by probabilistic record linkage. The study included 1602 children (33% with leukemia, 20% with lymphoma, 22% with central nervous system (CNS) tumors); with an overall 5-year survival of 77% (95%CI 75-79%). Higher SES, particularly parents' education, was associated with a lower 5-year cumulative mortality. Results varied by type of cancer with no association for leukemia and particularly strong effects for CNS tumor patients, where mortality hazard ratios for the different SES indicators, comparing the highest with the lowest group, ranged from 0.48 (95%CI: 0.28-0.81) to 0.71 (95%CI: 0.44-1.15). We conclude that even in Switzerland with a high quality health care system and mandatory health insurance, socioeconomic differences in childhood cancer survival persist. Factors causing these survival differences have to be further explored, to facilitate universal access to optimal treatment and finally eliminate social inequalities in childhood cancer survival. This article is protected by copyright. All rights reserved.

Inflammation as a psychophysiological biomarker in chronic psychosocial stress

The measurement of inflammation by biomarkers not only documents clinically relevant infections but also offers an important tool to pin point potentially harmful effects of chronic psychosocial stressors. This article focuses firstly on basic biology of inflammation and lists main biomarkers currently used in psycho-physiologic research. In the second part, the effects of the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system as pathways modulating stress-related inflammation are discussed. Furthermore, current evidence of how chronic psychosocial stressors are related to alterations in inflammatory activity is presented. In summary, job stress, low socioeconomic status, childhood adversities as well as life events, caregiver stress, and loneliness were all shown to exert effects on immunologic activity.

Reliability, construct and criterion validity of the KIDSCREEN-10 score: a short measure for children and adolescents' well-being and health-related quality of life

Background To assess the criterion and construct validity of the KIDSCREEN-10 well-being and health-related quality of life (HRQoL) score, a short version of the KIDSCREEN-52 and KIDSCREEN-27 instruments. Methods The child self-report and parent report versions of the KIDSCREEN-10 were tested in a sample of 22,830 European children and adolescents aged 8–18 and their parents (n = 16,237). Correlation with the KIDSCREEN-52 and associations with other generic HRQoL measures, physical and mental health, and socioeconomic status were examined. Score differences by age, gender, and country were investigated. Results Correlations between the 10-item KIDSCREEN score and KIDSCREEN-52 scales ranged from r = 0.24 to 0.72 (r = 0.27–0.72) for the self-report version (proxy-report version). Coefficients below r = 0.5 were observed for the KIDSCREEN-52 dimensions Financial Resources and Being Bullied only. Cronbach alpha was 0.82 (0.78), test–retest reliability was ICC = 0.70 (0.67) for the self- (proxy-)report version. Correlations between other children self-completed HRQoL questionnaires and KIDSCREEN-10 ranged from r = 0.43 to r = 0.63 for the KIDSCREEN children self-report and r = 0.22–0.40 for the KIDSCREEN parent proxy report. Known group differences in HRQoL between physically/mentally healthy and ill children were observed in the KIDSCREEN-10 self and proxy scores. Associations with self-reported psychosomatic complaints were r = −0.52 (−0.36) for the KIDSCREEN-10 self-report (proxy-report). Statistically significant differences in KIDSCREEN-10 self and proxy scores were found by socioeconomic status, age, and gender. Conclusions Our results indicate that the KIDSCREEN-10 provides a valid measure of a general HRQoL factor in children and adolescents, but the instrument does not represent well most of the single dimensions of the original KIDSCREEN-52. Test–retest reliability was slightly below a priori defined thresholds.

Aircraft noise, air pollution, and mortality from myocardial infarction

Objective: Myocardial infarction has been associated with both transportation noise and air pollution. We examined residential exposure to aircraft noise and mortality from myocardial infarction, taking air pollution into account. Methods: We analyzed the Swiss National Cohort, which includes geocoded information on residence. Exposure to aircraft noise and air pollution was determined based on geospatial noise and air-pollution (PM10) models and distance to major roads. We used Cox proportional hazard models, with age as the timescale. We compared the risk of death across categories of A-weighted sound pressure levels (dB(A)) and by duration of living in exposed corridors, adjusting for PM10 levels, distance to major roads, sex, education, and socioeconomic position of the municipality. Results: We analyzed 4.6 million persons older than 30 years who were followed from near the end of 2000 through December 2005, including 15,532 deaths from myocardial infarction (ICD-10 codes I 21, I 22). Mortality increased with increasing level and duration of aircraft noise. The adjusted hazard ratio comparing ≥60 dB(A) with <45 dB(A) was 1.3 (95% confidence interval = 0.96-1.7) overall, and 1.5 (1.0-2.2) in persons who had lived at the same place for at least 15 years. None of the other endpoints (mortality from all causes, all circulatory disease, cerebrovascular disease, stroke, and lung cancer) was associated with aircraft noise. Conclusion: Aircraft noise was associated with mortality from myocardial infarction, with a dose-response relationship for level and duration of exposure. The association does not appear to be explained by exposure to particulate matter air pollution, education, or socioeconomic status of the municipality.

Burden of abdominal obesity in cardiac rehabilitation patients: Results from the Swiss CaRe study

BACKGROUND: The burden of abdominal obesity (AO) and its association with other cardiovascular risk factors is not known in coronary artery disease (CAD) patients attending cardiac rehabilitation (CR). The aim of this study was, therefore, to investigate the prevalence of AO and differences in cardiovascular risk factors between AO and non-AO patients. METHODS: 415 consecutive male CAD patients (mean age 58 ± 11 years) attending a three-month outpatient CR programme were assessed. Differences in cardiovascular risk profile, including blood lipids, psychosocial and socioeconomic status and exercise capacity, were compared in relation to AO and corrected for obesity measured by body-mass index (BMI) in a multivariate analysis. RESULTS: Mean waist circumference was 102 ± 11 cm. Patients of lower educational level had a higher prevalence of AO (p = 0.021) than patients with a higher educational level. AO was significantly associated with diabetes (p = 0.003) and hypertension (p <0.001). In AO patients, HDL-C levels were lower (p <0.001) and triglyceride levels higher (p = 0.006) than in non-AO patients. There was no difference in exercise capacity between AO and non-AO patients, but AO patients had a higher resting heart rate (p = 0.021). CONCLUSION: AO is highly prevalent in CAD patients attending CR. AO is, independently of BMI, associated with metabolic lipid disorders and autonomic cardiovascular dysregulation, suggesting an increased cardiovascular risk. AO patients therefore need particular attention during CR and follow-up care.

[Psychosomatic medicine and arterial hypertension - love it or leave it?]

Over the last two decades modern psychosomatic research has found multiple evidence for an impact of psychosocial factors on the control of arterial blood pressure as well as the development of arterial hypertension. This narrative review focuses first on the current stress concept and factors that influence the degree of blood pressure change following a psychosocial stressor. Second, relevant psychosocial factors associated with blood pressure are presented such as marital status, social support, socioeconomic status and work conditions. In addition, the influence of personality and cognition on blood pressure will be discussed. The second part focuses on the outcome of cognitive-behavioral therapies and relaxation techniques as a means to effectively control blood pressure. In conclusion, there is now good evidence showing that psychosocial factors and stressors may increase blood pressure. The working environment, the socioeconomic status as well as aspects of personality and cognitive factors like rumination may also impact blood pressure with to an extent that is clinically relevant. With respect to therapeutic options, cognitive-behavioral interventions, combined with relaxation techniques all fitting the needs of the individual patient best can offer a clinically meaningful contribution of an effective blood pressure control.

The KIDSCREEN-27 quality of life measure for children and adolescents: psychometric results from a cross-cultural survey in 13 European countries

OBJECTIVE: To assess the construct and criterion validity of the KIDSCREEN-27 health-related quality of life (HRQoL) questionnaire, a shorter version of the KIDSCREEN-52. METHODS: The five-dimensional KIDSCREEN-27 was tested in a sample of 22,827. For criterion validity the correlation with and the percentage explained variance of the scores of the KIDSCREEN-52 instrument were examined. Construct validity was assessed by testing a priori expected associations with other generic HRQoL measures (YQOL-S, PedsQL, CHIP), indicators of physical and mental health, and socioeconomic status. Age and gender differences were investigated. RESULTS: Correlation with corresponding scales of the KIDSCREEN-52 ranged from r = 0.63 to r = 0.96, and r2 ranged from 0.39 to 0.92. Correlations between other HRQoL questionnaires and KIDSCREEN-27 dimensions were moderate to high for those assessing similar constructs (r = 0.36 to 0.63). Statistically significant and sizeable differences between physically and mentally healthy and ill children were found in all KIDSCREEN-27 dimensions together with strong associations with psychosomatic complaints (r = -0.52). Most of the KIDSCREEN-27 dimensions showed a gradient according to socio-economic status, age and gender. CONCLUSIONS: The KIDSCREEN-27 seems to be a valid measure of HRQoL in children and adolescents. Further research is needed to assess longitudinal validity and sensitivity to change.

Determinants of reduced walking speed in people with musculoskeletal pain

OBJECTIVE: Maintenance of good walking speed is essential to independent living. People with musculoskeletal disease often have reduced walking speed. We investigated determinants of slower walking, other than musculoskeletal disease, that might provide valuable additional targets for therapy. METHODS: We analyzed data from the Somerset and Avon Survey of Health, a community based survey of people aged over 35 years. A total of 2703 participants who reported hip or knee pain at baseline (1994/1995) were studied, and reassessed in 2002-2003; 1696 were available for followup, and walking speed was tested in 1074. Walking speed (m/s) was used as outcome measure. Baseline characteristics, including comorbidities and socioeconomic factors, were tested for their ability to predict reduced walking speed using multiple linear regression analysis. RESULTS: Age, female sex, and immobility at baseline were predictive of slower walking speed. Other independent risk factors included the presence of cataract, low socioeconomic status, intermittent claudication, and other cardiovascular conditions. Having a cataract was associated with a decrease of 0.10 m/s (95% CI 0.03, 0.16). Those in social class V had a walking speed 0.22 m/s (95% CI 0.126, 0.31) slower than those in social class I. CONCLUSION: Comorbidities, age, female sex, and lower socioeconomic position determine walking speed in people with joint pain. Issues such as poor vision and social-economic disadvantage may add to the effect of musculoskeletal disease, suggesting the need for a holistic approach to management of these patients.

Increased Framingham Coronary Heart Disease Risk Score in dementia caregivers relative to non-caregiving controls

BACKGROUND: Elderly individuals who provide care to a spouse suffering from dementia bear an increased risk of coronary heart disease (CHD). OBJECTIVE: To test the hypothesis that the Framingham CHD Risk Score would be higher in dementia caregivers relative to non-caregiving controls. METHODS: We investigated 64 caregivers providing in-home care for their spouse with Alzheimer's disease and 41 gender-matched non-caregiving controls. All subjects (mean age 70 +/- 8 years, 75% women, 93% Caucasian) had a negative history of CHD and cerebrovascular disease. The original Framingham CHD Risk Score was computed adding up categorical scores for age, blood lipids, blood pressure, diabetes, and smoking with adjustment made for sex. RESULTS: The average CHD risk score was higher in caregivers than in controls even when co-varying for socioeconomic status, health habits, medication, and psychological distress (8.0 +/- 2.9 vs. 6.3 +/- 3.0 points, p = 0.013). The difference showed a medium effect size (Cohen's d = 0.57). A relatively higher blood pressure in caregivers than in controls made the greatest contribution to this difference. The probability (area under the receiver operator curve) that a randomly selected caregiver had a greater CHD risk score than a randomly selected non-caregiver was 65.5%. CONCLUSIONS: Based on the Framingham CHD Risk Score, the potential to develop overt CHD in the following 10 years was predicted to be greater in dementia caregivers than in non-caregiving controls. The magnitude of the difference in the CHD risk between caregivers and controls appears to be clinically relevant. Clinicians may want to monitor caregiving status as a routine part of standard evaluation of their elderly patients' cardiovascular risk.