British Thoracic Society study of cryptogenic fibrosing alveolitis: current presentation and initial management. Fibrosing Alveolitis Subcommittee of the Research Committee of the British Thoracic Society

Our plain-English summary of British Thoracic Society study of cryptogenic fibrosing alveolitis: current presentation and initial management. Fibrosing Alveolitis Subcommittee of the Research Committee of the British Thoracic Society, by I.D. Johnston, R.J. Prescott, J.C. Chalmers, et al (Thorax, 1997).

The study

• Authors: I.D. Johnston, R.J. Prescott, J.C. Chalmers, R.M. Rudd
• Journal: Thorax
• Published: 1997;52(1):38-44
• Cited by: 147 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Mortality due to cryptogenic fibrosing alveolitis (CFA) is increasing, particularly in the elderly. Optimum management remains uncertain and previous studies of the disease have largely been from specialist centres. A national study was carried out of the presentation and initial management of CFA in the UK.

Methods: All respiratory physicians in England, Scotland and Wales were invited to enter patients with newly diagnosed CFA over a two year period. CFA was diagnosed on histological grounds or according to clinical criteria which included the absence of a defined connective tissue disorder or pneumoconiosis. Participating physicians (n = 150) completed a questionnaire at patient entry and at all subsequent follow up visits and death.

Results: A total of 588 patients (373 men, 63%) were studied of whom 441 (75%) were referrals from primary care. Their mean (SD) age was 67.4 (10.0) years and median duration of symptoms at presentation was 9.0 months. Clubbing was more common in men (203/373; 54%) than in women (86/ 215; 40%); 209 patients (36%) were graded as severely breathless at presentation. A history of dust exposure (organic or inorganic) was present in 274 patients (47%) of whom 87 had had some exposure to asbestos. Subjects exposed to dust were more likely to have smoked and had slightly higher mean lung volumes, but were otherwise indistinguishable from those not exposed in terms of clinical presentation, management, and outcome. Transbronchial biopsy specimens were taken in 164 patients (28%) and open lung biopsy specimens in 73 (12%), but 60% had no histological diagnostic procedure. Biopsy procedures were more likely to be performed in younger patients, those with better lung function, and those with a history of asbestos exposure. At presentation a decision not to initiate specific treatment was made in 284 cases (48%). The decision to initiate treatment was made predominantly on symptomatic grounds. Two years after the close of entry to the study 266 patients (45%) had died.

Conclusions: CFA is predominantly a disease of elderly patients and has a poor prognosis. Physicians generally considered CFA to be a clinical diagnosis and did not initiate treatment in up to half of patients at presentation.

In plain English

In this observational British Thoracic Society study, respiratory physicians in England, Scotland and Wales entered patients newly diagnosed with cryptogenic fibrosing alveolitis (CFA) between December 1990 and November 1992. Analysis covered 588 patients (mean age 67.4 years). Patients were included only if, in the participating physician's opinion, they had no occupational exposure sufficient for a pneumoconiosis diagnosis for state compensation. A history of dust exposure was reported by 274 patients (46.6%). Of these, 87 had some asbestos exposure, which physicians rated moderate or severe in 19. Dust-exposed patients were more likely to be current smokers and had slightly higher lung volumes. They showed no other significant differences, including survival to October 1994. A diagnostic procedure was done in 47 of 87 asbestos-exposed patients (54%) versus 189 of 501 others (38%). In all, 59.9% had no diagnostic procedure. Treatment was withheld at diagnosis in 284 patients (48.3%), and 266 (45.2%) had died by October 1994. The authors concluded CFA is predominantly a disease of the elderly and noted that asbestos exposure severity tended to be overestimated.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Prospective, national observational study of newly diagnosed patients, with data collected by questionnaire from participating physicians
• Who was studied: 588 patients with newly diagnosed cryptogenic fibrosing alveolitis (373 men, 215 women; mean age 67.4 years), entered by 150 respiratory physicians in England, Scotland and Wales between 1 December 1990 and 30 November 1992. Initially 611 patients were entered; 23 were withdrawn.
• Exposure: Self-reported history of dust exposure (asbestos, organic dust, other inorganic dust) taken from a structured occupational history. No fiber types were specified. Patients were excluded only if, in the participating physician's opinion, their occupational exposures would be accepted as a sufficient basis for a pneumoconiosis diagnosis for state compensation. Patients with asbestos exposure, including some rated moderate or severe, were included.
• Main results:
  • Asbestos exposure was reported by 79 men (21.2%), 8 women (3.7%) and 87 patients in total (14.8%).
  • Any dust exposure was reported by 212 men (56.8%), 62 women (28.8%) and 274 patients in total (46.6%).
  • Of the 87 asbestos-exposed patients, physicians rated exposure as moderate or severe in 19.
  • Of the four patients considered to have had severe asbestos exposure, no evidence of asbestosis was found at post mortem examination in two. In the other two, occupational histories suggested heavy exposure in only one.
  • A diagnostic procedure was more commonly performed in patients with a history of asbestos exposure: 47 of 87 (54%), compared with 189 of 501 (38%) without it (p<0.004).
  • Patients with any dust exposure were more likely to be current smokers and had slightly higher FVC, RV and TLC. There were no other significant differences from unexposed patients, including treatment decision and mortality. 172 (54.8%) of unexposed and 150 (54.7%) of exposed patients were alive at October 1994.
  • Comparing asbestos-exposed patients with the rest showed differences only in the same variables as for any dust exposure: smoking, lung volumes and the higher rate of diagnostic investigation.
  • In 59.9% of all patients, none of the four diagnostic procedures was performed (transbronchial, percutaneous or open lung biopsy, or bronchoalveolar lavage).
  • At diagnosis, physicians chose to observe rather than treat 284 patients (48.3%).
  • By October 1994, 266 patients (45.2%) had died. Death was considered primarily due to CFA in 53% of these cases.
• The authors' conclusion: The authors concluded that CFA is predominantly a disease of the elderly, with a mean age at presentation of 67 years.
• Limitations the authors state:
  • The questionnaire was not formally validated in areas such as symptoms, smoking and occupational histories.
  • Review of occupational histories suggested that the severity of asbestos exposure tended to be overestimated.
  • Only a few of the patients who died had a post mortem examination.
  • The biopsies taken were not reviewed by the study.
  • The study may have enrolled only 20 to 40% of all eligible patients nationally. It is likely to have missed patients who declined rapidly or whose diagnosis was initially uncertain.

Topics

Medical terms in this study, explained in our Lexicon: Pneumoconiosis, Clubbing, Biopsy, Asbestos Exposure, Prognosis.

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