Work package 5 – Development and implementation of methods

SP 5.1 Providing service and availability

One activity involves making available a questionnaire bank for measuring stress, burnout, and sleep and circadian (around-the-clock). A second activity provides a bank of actigraphs and physiological recorders for use by partners. This includes maintenance and some training of users. Senior researchers: Sverke, Westerlund, Kecklund. (P+R+O+I+W+E)
 

SP 5.2 Improvement of methods

These activities uses ongoing studies to evaluate measures on questionnaires for stress, burnout, sleepiness, sleep quality, sickness absence and presence. It also involves evaluations of measures of HR, HRV, immune parameters, endocrine variables, PSG and other indicators of sleep quality particularly in relation to stress. This work involves development of algorithms for better precision (for HRV, for example, or PSG analysis) as well as implementation of new statistical approaches to epidemiological data. Another activity is validation of the one-electrode PSG vs full PSG. The activites also investigates with HRV and sleep measures in twins under stress. Senior researchers: Hillert, Åkerstedt, Svartengren. (W+E+R+I+O)
 

SP 5.3 Establishing and maintaining large databases

A great asset of the center, in an international perspective, is our large, (both in terms of participants and number of variables per person), and unique prospective cohort databases. Senior researchers: Alexanderson, Westerlund, Sverke.

The groups of SSC have made strategic investments in establishing such databases. Some of them are:

• The LifeGene study, a national collaborative project designed to build up a resource to enable new research on the relationships among heredity, environment and lifestyle in a study base aiming for 500 000 Swedes.
   
• SLOSH, a nationally representative occupational cohort of 18,915 persons is followed prospectively with extensive questionnaires about work, non-work (e.g. retirement or unemployment), health, and private life every second year since 2006 and register data linked both prospectively and retrospectively. In the future we plan to add medical screening data for some participants.
   
• The RALF database comprising all participants in the Swedish Work Environment Surveys from 1989 onwards, including the SLOSH participants, plus all participants in the WOLF (WOrk Lipids and Fibrinogen) studies, in total over 160,000 persons with both questionnaire data and comprehensive register linkages, including the prescribed drug, inpatient, and 7/28 mortality registers, detailed data on sickness absence and employment, as well as data on the employers financial results.
   
• “All Sweden” the cohort of all 5.4 million people aged 16-64 living in Sweden in 2005. Detailed register data for each of the years 1990 to 2009 have been obtained regarding socio demographics, morbidity, mortality, and sickness absence (from Statistics Sweden, Board of Health and Welfare and the National Agency for Social Security). The corresponding data have been obtained for the cohorts of 2000 and 1995. For about 100,006 of these there is also survey data regarding self-reported health, life style, sleep, etc. The database provides unique possibilities to study associations between e.g. specific diseases and various outcomes in different subgroups.
   
• Working Life Survey, data from three repeated surveys to 5000 employees.
   

SP 5.4 Brain imaging

One focus of SSC is brain/immune mechanisms linking to stress and recovery to disease. Several fMRI and PET studies are planned. However, brain imaging requires specialized knowledge in several areas. To provide a long-term support, we have established a group with a fMRI/PET specialists (oneis being recruited). Senior Researchers: Lekander and Åkerstedt.
(P+R)
 

SP 5.5 Sleep laboratory

An important part of SSC is the study of recovery/sleep in relation to stress. For this purpose we have established a sleep laboratory with equipment and technical support. Senior Researchers: Åkerstedt and Hillert. (R+O+P)
 

SP 5.6 Analysis of multiple repeat data

Many of the studies conducted within the centre, both experimental and observational, comprise data with many repeat measurements for each participant. This confers major advantages statistically and regarding the possibilities to draw causal conclusions. We endeavor to apply the best available statistical methods to analyse these data, including own methodological development. Senior researchers: Westerlund, Åkerstedt, and Sverke. (E+W+R)