UK Household Longitudinal Study. Report on the Health and Biomarkers Consultation. Dieter Wolke and Scott Weich

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1 UK Household Longitudinal Study Report on the Health and Biomarkers Consultation Dieter Wolke and Scott Weich The consultation process was informed by an open meeting on 9 July 2007 at Warwick Medical School, by a meeting of the Advisory Board for Biomarker and Health Indicator (chair Professor Sir Michael Rutter) on 4 September at Regents College, London and through spontaneous e mail correspondence from experts and other interested individuals. A key source document for this consultation exercise was an independent report by Professor John Hobcraft (who is also a member of the Advisory Board) commissioned by the ESRC 1. The purpose of this report is to summarise the conclusions of the consultation exercise and to provide the UKHLS Board with specific recommendations for the design and implementation of field work 1. General principles 1.1 The primary aim of incorporating biomarkers and health indicators into the UKHLS is to facilitate research at the interface between biomedical and social sciences. 1.2 The UKHLS will be a longitudinal household study. Measures must be chosen that are appropriate to this design, and which maximise the capacity of this study to answer scientific questions. 1.3 The choice of measures needs to concentrate on areas that will give maximal scientific return in the area of interest. The study needs to be designed to meet multiple hypotheses, few of which will be known in advance. While broad aims and questions can be identified there may be many hypotheses that emerge within these. The study needs to be future proofed as far as possible, based on current knowledge. Although there are few pre ordained hypotheses, the design must be driven by scientific questions and methods; in addition there should be a hypothesis for which the biomarker is critically relevant, whether as an outcome or a pathway. 1.4 The UKHLS should concentrate on the collection of data on common outcomes and exposures. There will, however, inevitably be a degree of uncertainty and even disagreement about which common measures are of the greatest importance. 1 Hobcraft, J. (2007) Enabling transdisciplinary research in the UKHLS: Incorporating biomarkers and pathways into research on the interplays among social, economic, behavioural and health sciences. Report to the ESRC. 1

2 1.5 Measures of outcome and exposure must be relevant, and sufficiently common and important, across a broad age range. 1.6 Measurements need to be minimally invasive, able to be carried out quickly in the field, robust, valid and reliable. Although they may require special training, these will ideally be suitable for administration by trained lay interviewers rather than specialised nurses or similar. 1.7 The frequency at which data are collected and sample sizes need to be justified on the grounds of (i) likely variation over time and (ii) statistical power. Although there may be strong arguments for annual measurement in the entire UKHLS sample, this must be justified on scientific grounds. 1.8 Many parameters for the design of the study are fixed. There are time constraints for implementation, and significant budget constraints. These have clearly become more challenging as time has gone on, and it is possible that face to face interview time at each wave may be as little as 30 minutes per respondent. Thus, even if all of the above criteria are met, most measures will require specific and additional funding not provided by the ESRC UKHLS grant. 2. Recommendations Arising from the Consultation Exercise 2.1 Taking into account the WHO report on the major morbidities that reduce DALY s (Disability Adjusted Life Years) and are associated with significant dysfunction, labour participation and mortality, we aim to assess the major disabilities. A specific focus will be on two rapidly emerging areas that, at their extremes, are considered to be morbidities and are also related to significant morbidities: (1) body composition and (2) mental health, antisocial behaviour and wellbeing. The extremes of these measures have shown rapid increases in prevalence over recent decades and are considered epidemic and all are to be moderate to strong precursors for or comorbidity with other physical health problems such as diabetes or coronary heart disease or adult maladjustment. 2.2 The importance of collecting genetic material as part of UKHLS cannot be understated. From the perspective of the social scientist, the goal of behavioural genomics is to understand the developmental pathways between genes and behaviour, and this area of investigation and especially the study of gene x environment interactions is likely to prove increasingly important over time. As a household study, UKHLS is ideally placed to capture important (social) environmental exposures, increasing the salience of collecting genetic material. Deleted: health Deleted: 2

3 DNA can be collected at any time, and need only to be collected once for each participant. Current technological advances suggest that obtaining saliva is likely to prove satisfactory, obviating the need for blood sampling or the use of buccal swabs. Much of the financial, logistic and ethical aspects of DNA sampling have yet to be resolved, and will require more detailed investigation and planning as set out in the original UKHLS application. 2.3 There is a need to focus on health outcomes within the context of having good economic, demographic, and family/household information. This is one of the strengths of UKHLS. Priority should be given to ensuring that data about the social environment, family situation and relationships are collected. As well as facilitating gene x environment interaction research, it will also enable research into processes and outcomes around the time of key life transitions eg conception, birth, adolescence, employment and job loss, marriage and marital breakdown, retirement etc. 2.4 It should be considered whether health outcomes in the UKHLS ought to cover the full age range. It may well be unrealistic to try and collect good health measures across the full lifespan and as the comparative advantage of this study was having younger and middle ages, these groups should be the main focus. Limiting the number of children interviewed in each household should also be considered. It was suggested that the age range for the children s questionnaire should be as 10 and 11 year olds may not be capable of responding reliably about themselves. There are items which it would be better to ask of the mother or main carer such as whether the child is depressed or has any behavioural problems (at an early age). Children would be the best respondents for other questions such as their relationship with siblings, experience of being bullied and relationship with their parents. 2.5 With reference to the assessment of body composition, self report is of insufficient reliability and validity. There will be no alternative to anthropometric measurement of weight, height and waist circumference. These should be considered as the minimum UKHLS requirements. Body composition measures based on bioimpedance are desirable but would appear not to be feasible at this stage, for reasons of cost. 2.6 Within the BHPS, considerable interview time is given to the collection of data on the utilisation of health care. These data are little used, and serious consideration should be given to their omission from UKHLS. Additionally, the prospect of record linkage with NHS electronic records ought, in theory at least, enable these data to be collected more directly and without the biases arising from recall at interview. Deleted: to 3

4 2.7 In keeping with BHPS, there remains a need to collect data on the occurrence of chronic health problems (sometimes referred to as long term limiting illnesses) and disability, given the economic importance of these conditions. These data should be collected in a manner consistent with other surveys. 2.8 Consideration should be given to the use of some event triggered assessments, for instance after the occurrence of a traumatic life event in the year prior to interview. Another example are new pregnancy or birth. Onnovative instant internet/telephone questioning when these events occur should be considered. 3. Conclusions 3.1 (i) Core wave 1 health and biomarker measures in adults should include A Common (non psychotic) mental disorders: anxiety and depression A Mental well being A or B Basic anthropometric measures: weight, height and waist circumference A or B Long term limiting illnesses and disability A or B Chronic health problems A Prevalence and incidence of cancers A Prevalence and incidence of cardiovascular disease outcomes A Smoking, alcohol and substance misuse A Antisocial behaviour, victimisation and discrimination (A = annual assessment; B = bi annual or less frequent assessment required) 3.2 Collection of DNA is indicated, as soon as feasible. Saliva currently appears to be the most efficient means of collecting this. This would be once off exercise for each participant. Very careful consideration will need to be given to ethics and obtaining informed consent. 3.3 Highly desirable but lower priority measures at present include: B Family history data on anti social behaviour, drug and alcohol problems B Cognitive/ IQ testing [nb should be part of Psychological assessment module] A Cardio vascular measures (blood pressure and pulse rate) A Pain (e.g. back pain) A Sleep A Physical activity, fitness and nutrition (A = annual assessment; B = bi annual or less frequent assessment required) 3.4 Measures suggested but not recommended at this stage: Lung function Use of alternative therapies 4

5 3.5 Due consideration must be given to the validity of this data in young people for aome constructs, and in particular the need for informant accounts from parents and/or teachers. DW/SW 17 September