Asthma in adolescents, during the transition from child to adult, effects on physiological parameters and health related quality of life

Abstract

The aims of this thesis were to evaluate physiological and allergic aspects and consequences of asthma and possible correlation between Health Related Quality of Life (HRQOL) and atopy, lung function, bronchial hyper-responsiveness and regular physical exercise. Possible risk factors for deterioration among patients in their late teenage years prior to and following transfer to adult healthcare were examined. The study was designed to investigate possible differences between boys and girls, changes over time in these respects and additionally the impact of randomized referral to either a specialized asthma clinic or primary care on the same factors.

In this prospective study, conducted at the asthma/allergy clinic of the Childrens Hospital at Huddinge University 155 teenagers (69 females) with asthma were followed over a five year period. The patients were recruited consecutively and were screened employing spirometry, histamine challenge (to investigate bronchial hyper-responsiveness), skin prick test for allergy, and filled out The Living With Asthma Questionnaire both at the time of entry into the study and after 2 and 5 years of follow-up. An exercise test and questions about regular performed exercise were carried out at baseline and 5 years later. Adolescents with mild-to-moderate asthma were assigned randomly to care at the adult asthma clinic or primary care. When entering the study 89% were atopic. Lung-function increased from 94.0% of predicted (FEV1 mean value for the whole group (SD 12.9%) to 97.7% over the study period. Their Bronchial hyper-responsiveness decreased (PD20 for histamine chloride was median 440µg at entrance and increased five years later to 790µg) and working capacity decreased. At all three time points HRQOL for the men was generally better than that of the women. After five years HRQOL increased for both men and women but still the men had better HRQOL at the total score (of the scale) compared to the women. Young women who exercised regularly exhibited significant better HRQOL than those who did not whereas regular exercise had no impact on the HRQOL of the young men. Women with severe asthma demonstrated a poorer HRQOL than those suffering from mild-to-moderate asthma. Lung function, atopy, bronchial hyperresponsiveness did not exert any impact on HRQOL. Poor adherence to asthma treatment was associated with lower HRQOL as well as bronchial hyper-responsiveness. Adolescents with mild-to-moderate asthma showed no difference in HRQOL regardless of whether they received specialized treatment or primary care, lung function, atopy or bronchial hyper-responsiveness.

Suffering from asthma during late adolescence was associated with lower HRQOL for women than for men and this negative impact on adolescent women was enhanced when asthmatic symptoms were more severe. The HRQOL of both male and females improved as they grew older and entered adulthood. Lung function improved but hyper-responsiveness persisted. Female gender and poor adherence to asthma treatment exerted negative impact on bronchialhyper responsiveness and HRQOL which emphasizes the importance of health care programs that include patient education and support for adolescents with asthma as they are transferred from pediatric to adult health care. Mild-to-moderate asthma care can be equally handled in the primary care system.