Clinical characteristics governing treatment adjustment in COPD patients: results from the Swiss COPD cohort study.

BACKGROUND Chronic obstructive pulmonary disease (COPD) is a widespread chronic disease characterised by irreversible airway obstruction [1]. Features of clinical practice and healthcare systems for COPD patients can vary widely, even within similar healthcare structures. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) strategy is considered the most reliable guidance for the management of COPD and aims to provide treating physicians with appropriate insight into the disease. COPD treatment adaptation typically mirrors the suggestions within the GOLD guidelines, depending on how the patient has been categorised. However, the present study posits that the reasons for adjusting COPD-related treatment are hugely varied. OBJECTIVES The objective of this study was to assess the clinical symptoms that govern both pharmacological and non-pharmacological treatment changes in COPD patients. Using this insight, the study offers suggestions for optimising COPD management through the implementation of GOLD guidelines. METHODS In this observational cohort study, 24 general practitioners screened 260 COPD patients for eligibility from 2015-2019. General practitioners were asked to collect general information from patients using a standardised questionnaire to document symptoms. During a follow-up visit, the patient's symptoms and changes in therapy were assessed and entered into a central electronic database. Sixty-five patients were removed from the analysis due to exclusion criteria, and 195 patients with at least one additional visit within one year of the baseline visit were included in the analysis. A change in therapy was defined as a change in either medication or non-medical treatment, such as pulmonary rehabilitation. Multivariable mixed models were used to identify associations between given symptoms and a step up in therapy, a step down, or a step up and a step down at the same time. RESULTS For the 195 patients included in analyses, a treatment adjustment was made during 28% of visits. In 49% of these adjustments, the change in therapy was a step up, in 33% a step down and in 18% a step up (an increase) of certain treatment factors and a step down (a reduction) of other prescribed treatments at the same time. In the multivariable analysis, we found that the severity of disease was linked to the probability of therapy adjustment: patients in GOLD Group C were more likely to experience an increase in therapy compared to patients in GOLD Group A (odds ratio [OR] 3.43 [95% confidence interval {CI}: 1.02-11.55; p = 0.135]). In addition, compared to patients with mild obstruction, patients with severe (OR 4.24 [95% CI: 1.88-9.56]) to very severe (OR 5.48 [95% CI: 1.31-22.96]) obstruction were more likely to experience a therapy increase (p <0.0001). Patients with comorbidities were less likely to experience a treatment increase than those without (OR 0.42 [95% CI: 0.24-0.73; p = 0.002]). A therapy decrease was associated with both a unit increase in COPD Assessment Test (CAT) score (OR 1.07 [95% CI: 1.01-1.14; p = 0.014]) and having experienced an exacerbation (OR 2.66 [95% CI: 1.01-6.97; p = 0.047]). The combination of steps up as well as steps down in therapy was predicted by exacerbation (OR 8.93 [95% CI: 1.16-68.28; p = 0.035]) and very severe obstruction (OR 589 [95% CI: 2.72 - >999; p = 0.109]). CONCLUSIONS This cohort study provides insight into the management of patients with COPD in a primary care setting. COPD Group C and airflow limitation GOLD 3-4 were both associated with an increase in COPD treatment. In patients with comorbidities, there were often no treatment changes. Exacerbations did not make therapy increases more probable. The presence of neither cough/sputum nor high CAT scores was associated with a step up in treatment.