Health Insurance data Healthcare use and related costs, covered by the Dutch healthcare insurance, will be retrieved from Vektis; a Dutch organization which collects and manage health insurance claimed data of all health insurance companies in the Netherlands.This data is collected based on the Diagnosis Treatment Combination (DTC); a total set of activities carried out by the hospital and medical specialists. Additionally, data is collected regarding nursing days, visits at the outpatient clinic and emergency department, nursing homes, ambulance transport, consultation with general practitioner, paramedical care (including physiotherapist, occupational therapist, dietician and speech therapist), prescribed medication, mental healthcare and revalidation. The Vektis database contains data from all for healthcare insured citizens and covers 99% of the total Dutch population. Using patient's unique insurance number the investigators are able to merge patient's insurance data with the questionnaire data and medical data from the medical record at patient level.