The natural history of asthma in a primary care cohort

Presentation of respiratory symptoms prior to diagnosis in general practice: a case-control study examining free text and morbidity codes

OBJECTIVE

General practitioners can record patients' presenting symptoms by using a code or free text. We compared breathlessness and wheeze symptom codes and free text recorded prior to diagnosis of ischaemic heart disease (IHD), chronic obstructive pulmonary disease (COPD) and asthma.

DESIGN

A case-control study.

SETTING

11 general practices in North Staffordshire, UK, contributing to the Consultations in Primary Care Archive consultation database.

PARTICIPANTS

Cases with an incident diagnosis of IHD, COPD or asthma in 2010 were matched to controls (four per case) with no such diagnosis. All prior consultations with codes for breathlessness or wheeze symptoms between 2004 and 2010 were identified. Free text of cases and controls were also searched for mention of these symptoms.

RESULTS

592 cases were identified, 194 (33%) with IHD, 182 (31%) with COPD and 216 (37%) with asthma. 148 (25%) cases and 125 (5%) controls had a prior coded consultation for breathlessness. Prevalence of a prior coded symptom of breathlessness or wheeze was 30% in cases, 6% in controls. Median time from first coded symptom to diagnosis among cases was 57 weeks. After adding symptoms recorded in text, prevalence rose to 62% in cases and 25% in controls. Median time from first recorded symptom increased to 144 weeks. The associations between diagnosis of cases and prior symptom codes was strong IHD relative risk ratio (RRR) 3.21 (2.15 to 4.79); COPD RRR 9.56 (6.74 to 13.60); asthma RRR 10.30 (7.17 to 14.90).

CONCLUSIONS

There is an association between IHD, COPD and asthma diagnosis and earlier consultation for respiratory symptoms. Symptoms are often noted in free text by GPs long before they are coded. Free text searching may aid investigation of early presentation of long-term conditions using GP databases, and may be an important direction for future research.

Prognostic bases of asthma. Natural history?

Different causes of asthma have been established. The most common cause is conditioned to a genetic predisposition towards atopy (atopic asthma), although other factors can also give rise to bronchial inflammation, such as over-exposure to environmental irritants (occupational asthma), altered arachidonic acid metabolism (aspirin-induced asthma) and also exercise - in which different thermal and osmotic mechanisms are known to intervene. The prognosis of these different variants of asthma depends on the severity of the condition; patient age at onset of the disease; patient age at the time of diagnosis; the treatment provided; and adherence to therapy. The concept of "natural history" refers to the spontaneous evolution or course of the disease process in the absence of pathogenic or etiological treatment, with the provision of only symptomatic treatment. In order to gain increased certainty regarding the course of these patients, the study groups must present similar baseline characteristics in terms of the start and severity of the condition; the start of treatment; compliance; and the clinical and functional control findings.

Depression and panic disorder as predictors of health outcomes for patients with asthma in primary care

INTRODUCTION

Depression and panic disorder are widely acknowledged as complicating factors in asthma patients. However, their impact on health outcomes in primary care patients is less well examined. This study prospectively evaluated the impact of depression and panic disorder on outcomes of primary care patients with asthma over 1 year.

METHODS

At baseline, 256 asthma patients from 43 primary care practices completed self-report questionnaires including the Patient Health Questionnaire (PHQ), the Asthma Quality of Life Questionnaire (AQLQ), and a structured questionnaire evaluating asthma severity, hospitalisation and emergency visits. One year later, 185 (72.3%) patients completed the same questionnaire.

RESULTS

At baseline, 3.9% of patients suffered from major depressive disorder, 22.7% from minor depressive disorder, and 7.8% from panic disorder. In the year under evaluation, 17 patients (9.2%) received emergency home visits and 10 patients (5.4%) were admitted to a hospital. Depression at baseline predicted hospitalisation within the subsequent year (OR 6.1; 95% CI 1.5-24.6) and panic disorder predicted unscheduled emergency home visits (OR 4.8; 95% CI 1.3-17.7). Depression but not panic disorder predicted the AQLQ scales activity (p=0.001), symptoms (p=0.001), emotions (p=0.001) and environment (p=0.001) at follow-up.

CONCLUSIONS

Although rates of hospitalisation and emergency visits in primary care are low, the impact of psychiatric comorbidity on health outcomes for patients with asthma is substantial. It might be helpful to identify patients with psychiatric comorbidity by analysing reasons for hospitalisation and emergency visits. For these patients, intensifying care with psychiatric interventions might help to reduce inappropriate healthcare utilisation and avoid adverse outcomes.

Asthma score: predictive ability and risk factors

BACKGROUND

Definition of asthma as a continuous score is a promising tool for population studies that has not yet been fully evaluated.

OBJECTIVE

We assessed (i) the predictive ability of an asthma score against the occurrence of different asthma-related outcomes and (ii) the risk factors identified when using an asthma score.

METHODS

The European Community Respiratory Health Study II included subjects from the general population randomly studied during 1991-1993 who were followed up in the years 1998-2001, from 29 centres in 14 countries. A total of 8956 subjects were included. The asthma score consisted of a simple sum of the positive answers to five respiratory symptoms.

RESULTS

Asthma score at baseline showed a linear relationship with incidence of asthma, the occurrence of asthma attacks, use of asthma medication and bronchial reactivity at the end of the follow-up. Asthma score at the end of follow-up was associated with known risk factors at baseline such as IgE to grass, rhinitis or body mass index, in addition to passive smoking in men [average score ratio (RR) = 1.30; 95% confidence interval (CI) 1.09-1.50] or changes in body mass index (RR = 1.27; 95% CI 1.05-1.27, per each kg/m(2)).

CONCLUSION

The asthma score had good predictive ability against outcomes related with asthma and also good ability to detect risk factors. This encourages the use of the score as a measure of asthma in epidemiological studies on aetiology of asthma.

Vocational and working career of asthmatic adolescents is only slightly affected

INTRODUCTION

The aim of this study was to investigate whether teenagers and adolescents (10-22 years) with asthma or asymptomatic bronchial hyperresponsiveness, were more likely to experience vocational or professional career limitations in the future, as compared to non-asthmatic contemporaries.

METHODS

Data were used from a 14-year follow-up study in general practice, investigating the relationship between respiratory health in childhood and adolescence. At follow-up, the respiratory health status and information about career limitations were obtained.

RESULTS

There were no statistical significant differences between asthmatics (n=52) and non-asthmatics (n=154) in the proportion currently employed subjects, or contract type. Most examined career limitations were infrequently reported in both groups, but seemed to occur slightly more frequent among asthmatics. Asthmatics seemed to have an increased risk for limitations in daily activities both attributable to their respiratory health (OR=2.6, 95% CI [1.0; 7.0]) and all-cause (OR=1.8, 95% CI [0.9; 3.3]), and for absence from work all-cause (OR=1.7, 95% CI [0.9; 3.3]). However, the differences were in most cases in the magnitude of only a few days per year. Neither lung function nor bronchial hyperresponsiveness did predict absence from work, or limitations in daily activities.

CONCLUSION

Asthmatic young adults seem to experience somewhat more limitations in their vocational and professional careers. Nonetheless, the majority of the young asthmatics seem to be only slightly limited in their careers. In non-asthmatic young adults the presence of asymptomatic bronchial hyperresponsiveness does not seem to lead to career limitations.