Background: Chronic obstructive pulmonary disease affects nearly 400 million worldwide - over a million in the United Kingdom - and is the third leading cause of death. However, there is limited understanding of what prompts a diagnosis, how long this takes from symptom onset and the different approaches to clinical management by primary care professionals.
Objectives: Map out the clinical management and National Health Service contacts from symptom presentation to chronic obstructive pulmonary disease diagnosis and first acute exacerbation of chronic obstructive pulmonary disease in three time periods; construct risk prediction for first acute exacerbation of chronic obstructive pulmonary disease.
Design: Retrospective cohort study and cross-sectional survey.
Setting: Primary care.
Participants: Patients with incident chronic obstructive pulmonary disease aged > 35 years in England.
Interventions: None.
Main outcome measures: First acute exacerbation of chronic obstructive pulmonary disease.
Data sources: Clinical Practice Research Datalink Aurum; new online survey.
Results: Forty thousand five hundred and seventy-seven patients were diagnosed between April 2006 and March 2007 (cohort 1), 48,249 between April 2016 and March 2017 (cohort 2) and 4752 between March and August 2020 (cohort 3). The mean (standard deviation) age was 68.3 years (12.0); 47.3% were female. Around three-quarters were diagnosed in primary care, with a slight fall in cohort 3. Compliance with National Institute for Health and Care Excellence diagnostic guidelines was slightly higher in cohorts 2 and 3 for all patients; 35.8% (10.0% in the year before diagnosis) had all four elements met for all cohorts combined. Multilevel modelling showed considerable between-practice variation in spirometry. The survey on the charity website had 156 responses by chronic obstructive pulmonary disease patients. Many respondents had not heard of the condition, hoped the symptoms would go away and identified various healthcare-related barriers to earlier diagnosis. Clinical Practice Research Datalink analysis showed notable changes in post-diagnosis prescribing from cohort 1 to 2, such as increases in long-acting muscarinic antagonist (21.7-46.3%). Triple therapy rose from 2.9% in cohort 2 to 11.1% in cohort 3. Documented pulmonary rehabilitation rose from just 0.8% in cohort 1 to 13.7% in cohort 2 and 20.9% in cohort 3. For all patients combined, the median time to first acute exacerbation of chronic obstructive pulmonary disease in patients who had one was 1.4 years in cohorts 1 and 2. Acute exacerbation of chronic obstructive pulmonary disease prediction models identified some consistent predictors, such as age, deprivation, severity, comorbidities, post-diagnosis spirometry and annual review. Models without post-diagnosis general practitioner actions had a c-statistic of around 0.70; the highest c-statistic was 0.81, for cohort 2 with post-diagnosis general practitioner actions and 6-month follow-up. All models had good calibration. The three most important predictors in terms of their population attributable risks were being a current smoker and offered smoking cessation advice (32.8%), disease severity (30.6%) and deprivation (15.4%). The highest population attributable risks for variables with adjusted hazard ratios < 1 were chronic obstructive pulmonary disease review (-27.3%) and flu vaccination (-26.6%).
Limitations: Symptom recording and chronic obstructive pulmonary disease diagnosis vary between practice; predicted forced expiratory volume in 1 second had many missing values.
Conclusions: There has been some improvement over time in chronic obstructive pulmonary disease diagnosis and management, with large changes in prescribing, though patient and system barriers to further improvement exist. Data available to general practitioners cannot generate risk prediction models with sufficient accuracy.
Future work: It will be important to expand the COVID-era cohort with longer follow-up and augment general practitioner data for better prediction.
Study registration: This study is registered as Researchregistry.com: researchregistry4762.
Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme (NIHR award ref: 17/99/72) and is published in full in Health and Social Care Delivery Research; Vol. 12, No. 43. See the NIHR Funding and Awards website for further award information.
Keywords: ACUTE EXACERBATION; CHRONIC OBSTRUCTIVE PULMONARY DISEASE; CLINICAL GUIDELINES; EARLY DIAGNOSIS; ELECTRONIC HEALTH RECORDS; OBSERVATIONAL STUDY; RISK PREDICTION; SPIROMETRY.
Chronic obstructive pulmonary disease is often caused by smoking and affects over 1 million people in the United Kingdom. While there are well-established treatments, less is known on where and when patients get the diagnosis, how general practitioners investigate their symptoms and to what extent the first major flare-up (‘acute exacerbation’) can be predicted and prevented. Using a research database of general practitioner consultation records linked to hospital admissions and the national death register, we described patient characteristics, general practitioner actions before and following diagnosis, and, with statistical models, predictors of the first exacerbation. We looked at three time periods according to the date of diagnosis: April 2006–March 2007 (cohort 1), April 2016–March 2017 (cohort 2) and March–August 2020 (cohort 3). We sent patients a questionnaire asking about their experiences of developing symptoms, seeking medical help and getting diagnosed. We analysed records of over 70,000 patients in total. The majority were diagnosed by their general practitioner. In cohorts 2 and 3, general practitioners did the recommended tests more than in cohort 1, though in the year before diagnosis, only 10% of patients had all four done. Our survey found that many people were unaware of chronic obstructive pulmonary disease and its symptoms before their diagnosis but also that some felt they were not taken seriously by the medical team and that their diagnosis was delayed. There were improvements over time in prescribing. Most patients were offered the flu jab. Older patients, current smokers and those with other conditions such as heart failure had higher risk of an acute exacerbation. The statistical models did not perform well enough to be used to guide decision-making. Despite some improvements over time, there remain opportunities for better recognition of the condition among patients and general practitioners alike. Future work should more fully assess the impact of COVID-19.