Harmonisation of mental health measures in British birth cohorts

Lead Research Organisation: University College London
Department Name: Social Science

Abstract

Major depression and anxiety disorders appear in the top 10 causes of global burden of disease, with major depression also being the second leading cause of disability worldwide and a major contributor to the burden of suicide and ischemic heart disease. The public health burden of these common psychological disorders is estimated to continue to increase. While the huge costs to society, and to the economy, of poor mental health are undisputed (4) and inequalities due to both social causation and selection are well documented, the idea that experiences of mental distress in adulthood are increasing across generations has not been much discussed, and yet if true as recent evidence suggests, is of major societal and population health significance, especially considering the effects of population ageing. Understanding the development of mental health symptoms over the life course and the investigation of secular mental health trends require comparable measures within and across cohorts, but with rare exceptions the measurement conditions that allow reliable comparisons have not been investigated.

Planned Impact

We will disseminate our findings to a wide range of academic and other audiences. The team is multidisciplinary (economics, psychology, population health, epidemiology, applied statistics) and this expands the potential dissemination network. We will present our findings in national and international conferences and via an article in a high-impact, peer-reviewed journal. We have a strong track record of publishing in leading international journals, and established links with academics from various disciplines based in universities in the UK and internationally. We will also run a 1-day workshop featuring presentations of the harmonisation report and user guide as well as our other findings and discussion of policy and practice implications. As well as providing guidance for analysts on the use of mental health measures, our findings will be valuable for future cohorts, by identifying which mental health measures have the desirable measurement properties and are therefore more likely to add most value to future studies and/or sweeps of existing studies. The project will be supported by the impact and communications infrastructure at the Centre for Longitudinal Studies (CLS), including its award-winning Communications Team. Media coverage of CLS work has proven to be an effective way of reaching many of CLS's target audiences, including policymakers, practitioners and the general public. CLS has successfully secured coverage by the BBC, Channel 4, Guardian, Telegraph, Times, Financial Times, Independent, among others. Our work will be fitted into CLS's wider Impact Strategy, meaning we will have access to CLS's full range of communications tools and channels. We will also capitalize on the network of impact partners established within the ESRC funded CLS Cross Cohort Research Programme and work closely with the National Children's Bureau and the Mental Health Foundation to maximise the impact of our findings by helping us to target interested people, organisations and stake holders more effectively.

Publications

10 25 50
 
Description The UK's world-renowned birth cohorts have collected repeated measures of mental health from the same individuals over the course of their lives. These scientific resources have allowed researchers to monitor the evolution of mental health across life and have greatly enhanced our understanding of its antecedents and consequences over the life course. Much of the information in the studies has been collected through self-report questionnaires, a key method of assessing mental health. Despite these measures being widely used, we have yet to unlock their full potential. You see, these mental health measures vary, both within and between cohorts. It's unsurprising really - the data have been collected over decades, at different periods and from various teams, and the psychological and psychiatric assessment science evolved parallel to the studies.

Overcoming obstacles through harmonisation: Under a CLOSER initiative, colleagues and I at the UCL Centre for Longitudinal Studies, in collaboration with the UCL Department of Clinical, Health and Educational Psychology, the MRC Unit for Lifelong Health and Ageing at UCL and the Bristol Medical School, have been working on how to overcome these obstacles in five British birth cohorts:

MRC National Survey of Health and Development (1946 birth cohort)
National Child Development Study (1958 birth cohort)
1970 British Cohort Study
Avon Longitudinal Study of Parents and Children (Children of the 90s)
Millennium Cohort Study.

The primary aim of our work is to make it easier for researchers to use multiple measures that assess a similar broad construct, but do so by asking different questions. We harmonised the data - a process of recoding or modifying variables so that they are comparable across studies. We focused on childhood measures of internalising and externalising symptoms, and adult measures of common mental disorders (e.g. psychological distress, depression and anxiety symptoms).

The process

We used a two-step process to harmonise each measure: Three psychologists went through all mental health questions in the five cohorts. Working separately, they assigned the symptom to which they believed that particular question taps into (see table below for an example). Interrater agreement at this stage was >90%. The three psychologists then compared their decisions, and deliberated on points of disagreement before reaching a final decision. We found various subsets of items in the different cohorts that tap into the same symptom, and thus can be used for longitudinal analysis or between-cohort comparisons. A very encouraging finding for all possible combinations of harmonised items was that the psychometric properties of these sets of items were satisfactory, and they also correlated highly with the original scales from which they were derived.

Even when identical measures between and within cohorts have been used, there are still issues that may bias mental health assessments. For example, it is well known that data from self-reported measures are likely to be biased by the respondent's personality and/or circumstances. Additional sources of error may arise from differences in the comprehension of items, and in response tendencies such as response style and social desirability (which may also vary over time, between groups, or across generations). Within the context of British birth cohorts, these sources of measurement error can also be thought of as age, period and cohort effects. As participants age, they may become more likely to endorse a mental health symptom (age effect), younger generations may have increased awareness of mental health symptomatology (cohort effect), or particular circumstances at the time of the interview may lead survey participants to over/underreport mental health symptoms (period effect). Error can also be introduced by differences in the measurement mode between sweeps of longitudinal surveys, or within the same mode by the preceding survey questions before the mental health items appear.

We investigated the measurement equivalence of mental health measures that have been administered in various sweeps within and across these cohorts. To do so, we employed methods within the generalised latent variable modelling framework, and tested for measurement equivalence within and between cohorts. We found that even the most conservative models that impose an identical measurement model within and across cohorts, as well as gender, did fit the data, implying that potential sources of bias such as age, period, cohort effects, and survey design do not influence the way participants interpret and respond to mental health items.
Exploitation Route Considering that the public health burden of depression and anxiety - the major components of psychological distress - is estimated to continue to increase future research to identify modifiable factors to shift the distribution of risk is needed. As such, our findings have the potential to inform the application of dynamic longitudinal models of mental health assessments in longitudinal surveys, studies that seek to identify high-risk life periods and facilitate prevention and early detection, as well as cross-cohort comparisons of life-course profiles that can help us elucidate whether risk periods are stable or vary according to changing social and economic circumstances. Our findings have implications for survey design, as the longitudinal equivalence and measurement properties of the Malaise Inventory make its inclusion in future sweeps of the two cohorts, but also in other longitudinal surveys, desirable.
Sectors Education

 
Description Centre for Society and Mental Health 
Organisation King's College London
Department Institute of Psychiatry, Psychology & Neuroscience
Country United Kingdom 
Sector Academic/University 
PI Contribution I co-lead the cohorts and longotuidnal surveys work package and contribute expertise in longitudinal data analysis and methodology
Collaborator Contribution The Centre for Society & Mental Health explores today's changing world and taps into the social factors that shape and promote mental ill health. We bring together world-leading expertise in psychiatry, neuroscience and the social and human sciences to analyse the major social, economic and cultural transformations affecting our mental health. This includes working closely with those who have experienced mental ill health, as well as with government, non-governmental organisations, policy members, planners, architects and local mental health and community groups to translate our research into practices that will improve the lives of all who are affected.
Impact No outputs yet as the project just started
Start Year 2020
 
Description Blog post: Unlocking the potential of mental health measures in the British birth cohorts 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Various researchers interested in mental ehalth contacted the tema for further information on mentla health measurement in British birth cohorts
Year(s) Of Engagement Activity 2019
URL https://www.closer.ac.uk/news-opinion/blog/unlocking-potential-mental-health-measures-british-birth-...
 
Description Conference paper: Secular Trends in Childhood Emotional and Behavioural Problems: Evidence from the British Birth Cohorts 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact Conference presentation at Society for Longitudinal and Life Course Studies International Conference 2019. University of Potsdam, Germany.
Year(s) Of Engagement Activity 2019
URL https://www.closer.ac.uk/event/slls-conference-2019/
 
Description Conference presentation: Harmonisation of mental health measures in the British birth cohorts 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact Conference presentation at "Preparing for the future II: international approaches to challenges facing the longitudinal population studies reservation. University College London".
Year(s) Of Engagement Activity 2020
URL https://www.closer.ac.uk/wp-content/uploads/Preparing-for-the-future-II-Full-report-FINAL.pdf
 
Description Conference presentation: Harmonisation of mental health measures in the British birth cohorts 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact Conference Presentation at International Federation of Psychiatric Epidemiology Conference, Sao Paolo, Brazil.
Year(s) Of Engagement Activity 2019
 
Description Demographic shifts and population mental healt: a life course perspective 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact About 500 memebrs of the public wahted my talk the the Institute of Demography, Economy and Geography, Spanish National Research Council via Twitter, Vimeo and other media paltforms. About 50 Academics were present at the talk
Year(s) Of Engagement Activity 2019
URL http://demografia.tv/video/d4785fa5d6c99d8/Prof-George-Ploubidis-Demographic-shifts-and-population-m...
 
Description Harmonisation of Mental Health Measures in the British Birth Cohorts 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact Conference presentation at Society for Longitudinal and Life Course Studies International Conference 2019. University of Potsdam, Germany.
Year(s) Of Engagement Activity 2019
URL https://www.closer.ac.uk/event/slls-conference-2019/
 
Description Harmonising mental health measures from the British birth cohorts 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact A half-day workshop hosted at the Centre for Longitudinal Studies, University College London in which the results from our harmonisation project, and best practices in harmonisation, were discussed.
Year(s) Of Engagement Activity 2019
URL https://www.closer.ac.uk/event/harmonising-mental-health-measures/
 
Description Online webinar: Investigating mental health in the UK - what data can I use? 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact Online webinar as part of ESRC data resources webinar series (https://www.ukdataservice.ac.uk/news-and-events/eventsitem/?id=5538)
Year(s) Of Engagement Activity 2019
URL https://www.ukdataservice.ac.uk/news-and-events/eventsitem/?id=5538
 
Description Psychological distress over the life course: Evidence from the 1946, 1958 and 1970 British birth cohorts 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Presentation at the Annual Population Association of America meeting, Austin, April 2019
Year(s) Of Engagement Activity 2019
 
Description • Symposium (three presentations) at the Instituto Federal de Pernambuco (IFPE) 2019 conference in Sao Paulo 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact We organised a symposium at the IFPE conferecne in Sao Paulo, Brazil. Work on harmonisation of mental health measures in the British borth cohorts and a comparison of lifelong mental health across generations was presented.
Year(s) Of Engagement Activity 2019