This supplementary information is presented as submitted by the corresponding author. It has not been copy-edited by NTvG.
Asthma, COPD and respiratory allergy are important chronic respiratory diseases that affect more than one million people in the Netherlands. The economic burden on society and individuals is considerable, due to the notable healthcare utilization and production losses associated with these conditions. In this study, we determined the societal costs of asthma, COPD and respiratory allergy in the Netherlands for the year 2007 and estimated future healthcare costs by means of projections.
The prevalence of the diseases was based on nationally representative primary care registries and was obtained from the website of The National Public Health Compass and from Statistics Netherlands. Data regarding health care costs were based on national registries and surveys. The following components of health resource were retrieved: disease-related general practitioner, physician and physiotherapy visits were obtained from a national survey among patients with asthma and COPD. For respiratory allergy, general practitioner and physician visits were based on the literature. Hospital admissions and length of stay were derived from the website of Statistics Netherlands. Prescribed medication was obtained from the Landelijk InformatieNetwerk Huisartsen, a nationwide primary care register. Prescribed medication for the three diseases and oxygen use for COPD patients were combined with cost data of the Drug Information System of the Health Care Insurance Board. Information on the uptake of the influenza vaccination was derived from the literature. Data on home care and nursing homes were extracted from the website of the Dutch Cost of Illness Study. Data on COPD-related lung transplantations were obtained from the Dutch Transplantation Foundation. Unit costs were gathered from standard unit cost lists and all costs were expressed in Euros price level of 2007.
The quantity of asthma- and COPD-related sick leave and work incapacity in the Netherlands was based on the study: “Werken met een chronische longaandoening”. Production losses were calculated using the friction-cost method. No reliable data were available concerning productivity losses for respiratory allergy.
Projections were made to estimate disease prevalence for the period 2007 to 2032, using merely demographic data for respiratory allergy and a simulation model for asthma and COPD. The disease specific model projections of prevalence were combined with scenarios for healthcare costs developed by the Netherlands Bureau for Economic Policy Analysis.
Healthcare costs for asthma, COPD and respiratory allergy in 2007 were estimated at 287, 415 and 103 million euros respectively. This is on average annually 530, 1400 and 170 euros per patient with asthma, COPD and respiratory allergy. Main cost driver for all diseases was medication; hospitalizations and nursing lead to high medical costs for COPD patients as well. Annual costs of sick leave due to asthma were on average 1200 euros and for COPD 1900 euros per employee. Sick leave associated costs were highest among employees aged 55 years and over. The mean annual costs of work incapacity of an employee with COPD were 1200 euros.
Up to 2032, projections show an increase of the number of asthma patients from 443,000 to 567,000; the number of patients with COPD will rise from 335,000 to 600,000. The primary causes for these increases are population growth and ageing. The number of patients with a respiratory allergy is likely to remain stable at 625,000 patients in this period, as the disease is less common among the elderly. The health care costs for respiratory allergy are expected to rise by 73%, those for asthma to double, and those for COPD to triple by 2032.
Patients with asthma and COPD have significant healthcare costs. Costs of sick leave are substantial for employees with asthma and COPD. In addition, the costs of work incapacity for employees with COPD are high. Up to 2032 the number of patients with asthma and COPD will rise as well as the health care costs of asthma and COPD. The expected rise in the number of patients with asthma, COPD or respiratory allergy and the associated costs of healthcare and production losses provide important information for healthcare policy in the Netherlands. Efficient prevention and treatment of the diseases are indicated, especially the efficient use of medication. As the number of elderly with asthma or COPD will rise, providing them with support is essential.