Review of Kleinsorge, Pasha, Boesing et al. (2023) Treatment Adjustment in (Swiss) COPD Patients
Clinical Characteristics Governing Treatment Adjustment in COPD Patients
Kleinsorge, Pasha, Boesing et al. · Swiss Medical Weekly, 153:40114 · 2023
In Swiss primary care, COPD treatment adjustments are driven primarily by spirometric severity and GOLD group classification — not by patient-reported symptoms. Comorbidities actively reduce the probability of treatment change, and exacerbations do not reliably trigger step-ups in therapy.
Research Question
What clinical characteristics govern pharmacological and non-pharmacological treatment adjustments in COPD patients managed within primary care, and how well do these decisions align with GOLD guideline recommendations?
Why It Matters
COPD affects approximately 11.7% of the global population and is the fourth leading cause of death worldwide. Despite GOLD guidelines providing clear treatment pathways, real-world clinical practice diverges substantially from those recommendations — contributing to under- and over-treatment, and persistent morbidity.
Key Gap Addressed
It was unclear which specific patient characteristics actually trigger treatment changes in primary care settings. Patient-reported tools like the CAT questionnaire are recommended by GOLD but seldom used systematically — and it was unknown whether symptom scores influenced therapy decisions in practice.
Main Contribution
This study quantifies, using multivariable mixed models, the associations between disease features and treatment adjustment direction. It shows that spirometric severity (GOLD FEV1 grades) and GOLD group C status predict step-ups, while comorbidities suppress treatment changes — even when COPD symptoms worsen. This has direct implications for guideline dissemination and GP education.
Treatment Change Breakdown
| Change Type | Visits (n) | Share of Changes | Key Predictors |
|---|---|---|---|
| Step Up Only | 94 | 49.5% | GOLD Group C; severe/very severe FEV1 obstruction; no comorbidities |
| Step Down Only | 62 | 32.6% | Higher CAT score; prior exacerbation; GOLD Group C |
| Step Up + Step Down Simultaneously | 34 | 17.9% | Exacerbation; very severe obstruction (OR 589) |
| No Change | 500 | 72% of all visits | — |
■ Disease & Staging ■ Measurement Tools ■ Treatment Concepts ■ Study Methodology
Disease & Staging
Measurement Tools
Treatment Concepts
Study Methodology
An observational cohort of 195 Swiss primary care COPD patients was followed over multiple visits from 2015–2019. Multivariable mixed logistic models identified predictors of three treatment change categories: step-up, step-down, and simultaneous step-up and step-down.
Study Design & Setting
- Sub-study of the ongoing Swiss COPD Cohort Study (multicentre, population-based, observational)
- 24 general practitioners from multiple Swiss cantons recruited patients
- Baseline visit followed by re-examinations every 6 months
- Ethics approval from EKNZ and cantonal committees; ClinicalTrials.gov: NCT02065921
Inclusion Criteria
- Post-bronchodilator FEV1/FVC <70% (spirometric COPD confirmation)
- Age >40 years
- Smoker or ex-smoker with at least 20 pack-years
- Written informed consent
- At least one follow-up visit within 12 months of baseline
Data Collection
- Baseline: demographics, smoking history, spirometry (per ERS/ATS standards), CAT score, mMRC, comorbidities, medications
- Follow-up visits: CAT, mMRC, exacerbation history, hospitalisations, medication changes, pulmonary rehabilitation
- Data entered into a central electronic database (RDE Light)
- Comorbidities recorded: asthma, cardiovascular diseases, diabetes, malignant diseases
Primary Outcome Definition
- A treatment change was defined as any change in substance class of medication, or the new prescription of pulmonary rehabilitation
- Switching within the same substance class did not count as a change
- Three mutually exclusive outcome categories: (1) step-up only, (2) step-down only, (3) simultaneous step-up and step-down
Statistical Approach
- Descriptive statistics: means ± SD for continuous variables; frequencies for categorical variables
- Separate univariable and multivariable generalised logistic mixed models (SAS GLIMMIX procedure, v9.4)
- Fixed effects: disease characteristics (CAT, comorbidities, exacerbation, GOLD group, GOLD FEV1 stage, cough/sputum); random effect: individual patient
- mMRC excluded from multivariable model due to collinearity with GOLD group assignment
- Hypothesis testing: Wald test; p-values interpreted descriptively
Sample & Exclusions
- 260 patients screened; 253 with spirometric COPD diagnosis
- 48 excluded for missing follow-up or visits >1 year apart
- 10 excluded for missing medication data
- Final analytic sample: 195 patients / 690 visits
- 32.6% of the overall recruited population lacked spirometric confirmation of COPD — a notable quality finding in itself
Select cited works central to interpreting the study's findings. Click any card to expand.
Clinical Characteristics Governing Treatment Adjustment in COPD Patients: Results from the Swiss COPD Cohort Study
Citation
Kleinsorge L, Pasha Z, Boesing M, Abu Hussein N, Bridevaux PO, Chhajed PN, Geiser T, Joos Zellweger L, Kohler M, Maier S, Miedinger D, Tamm M, Thurnheer R, von Garnier C, Leuppi JD. Clinical characteristics governing treatment adjustment in COPD patients: results from the Swiss COPD cohort study. Swiss Med Wkly. 2023;153:40114. DOI: 10.57187/smw.2023.40114
About This Study
An observational cohort sub-study drawing on data from 195 COPD patients recruited by 24 Swiss general practitioners between 2015 and 2019 (690 total visits). Using multivariable mixed logistic models, the study identified clinical predictors of three types of treatment adjustment — step-up, step-down, and simultaneous step-up and step-down — with the primary aim of understanding how real-world COPD management in primary care diverges from GOLD guideline recommendations.
Funding was provided by Boehringer Ingelheim GmbH, GSK AG Switzerland, and Novartis AG Switzerland, with declared non-involvement in study design, data collection, or manuscript preparation. Ethical approval: EKNZ (EK Nr. 170/06); ClinicalTrials.gov: NCT02065921.
View paper → doi:10.57187/smw.2023.40114GOLD Global Strategy for COPD Diagnosis, Management and Prevention
Why It Matters Here
The GOLD strategy is the primary normative framework against which all treatment decisions in this study are evaluated. It defines the ABCD grouping system, specifies recommended pharmacological regimens per group, and endorses the CAT and mMRC as standard assessment tools. The 2017 revision introduced the separation of spirometric grading from symptom-based grouping — a refinement central to this study's analytic structure.
A 2022/2023 update proposed merging Groups C and D into a single Group E for frequent exacerbators. This is directly referenced in the discussion, as the study's finding that Group C is associated with all types of treatment change (up, down, and both) may have contributed to the rationale for that consolidation.
View guidelines → goldcopd.orgAdherence to GOLD Recommendations among Swiss Pulmonologists and General Practitioners
Why It Matters Here
Marmy et al. provide the most directly comparable Swiss-context finding: up to 53% of COPD patients in their study were not consistently treated according to GOLD 2017 recommendations. This corroborates Kleinsorge et al.'s observation of real-world guideline deviation and underlines the persistence of the gap between evidence-based guidelines and Swiss primary care practice.
Both studies emphasise the under-use of standardised patient-reported outcome measures (CAT, mMRC) by general practitioners — a finding that, in Kleinsorge et al., may explain why symptom scores did not predict treatment changes.
View paper → doi:10.1080/15412555.2020.1859469Determinants for Changing the Treatment of COPD: A Regression Analysis from a Clinical Audit
Why It Matters Here
López-Campos et al. investigated the same research question in a Spanish clinical audit context and found that disease exacerbation was the main driver of treatment intensification among those whose treatment was changed. This directly contrasts with Kleinsorge et al.'s finding that exacerbation did not predict a step-up in the Swiss cohort — one of the study's most unexpected results.
The comparison highlights how healthcare system context, practice culture, and guideline implementation infrastructure can produce meaningfully different real-world treatment patterns even when the clinical guidelines are the same.
View paper → doi:10.2147/COPD.S103614General Practitioner's Adherence to COPD GOLD Guidelines: Baseline Data of the Swiss COPD Cohort Study
Why It Matters Here
Jochmann et al. represent the earlier baseline report from the same Swiss COPD Cohort Study. They documented that general practitioners often did not use the CAT questionnaire and failed to perform spirometry on a routine basis — the same structural deficiencies that Kleinsorge et al. continue to observe a decade later. This continuity is sobering: it suggests these gaps in guideline adherence are persistent features of primary care COPD management in Switzerland, not transient deficiencies.
View paper → doi:10.4414/smw.2010.13053Compliance of Pharmacotherapy with GOLD Guidelines: A Longitudinal Study in Patients with COPD
Why It Matters Here
Grewe et al. found that drug prescriptions for COPD were only partially compliant with GOLD guidelines (59.1% adherence rate) and noted that more severely ill patients were more likely to receive guideline-concordant treatment. This finding aligns with Kleinsorge et al.'s results, which similarly show that severe to very severe spirometric obstruction is a stronger predictor of treatment adjustment than symptom burden.
Together, these studies suggest a consistent pattern in Swiss care: spirometric severity is a more actionable decision trigger than patient-reported symptoms, possibly due to the objective and quantitative nature of spirometry results versus subjective questionnaire scores.
View paper → doi:10.2147/COPD.S240444In Swiss primary care, COPD treatment adjustment is governed by objective spirometric severity rather than patient-reported symptom burden — and the presence of comorbidities acts as a structural barrier to treatment change, even as guidelines demand the opposite.
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Spirometric Severity Drives Step-Up Decisions
Severe (OR 4.24) and very severe (OR 5.48) airflow limitation were the strongest independent predictors of treatment intensification. GOLD Group C membership was also associated with step-ups (OR 3.34). This suggests that objective lung function data, rather than patient-reported symptoms, is the dominant trigger for action in real-world primary care.
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CAT Score and Cough Were Not Associated with Treatment Changes
Despite GOLD guidelines recommending the CAT as a central tool for patient categorisation and treatment decisions, neither CAT score nor the presence of cough and sputum was associated with step-ups in this cohort. This points to systematic under-use of patient-reported outcome measures in practice — a gap with direct implications for GP education and system design.
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Comorbidities Suppress Treatment Intensification
With 71% of patients having at least one comorbidity, the finding that comorbidities reduced the likelihood of a step-up (OR 0.42) is clinically significant. Physicians may attribute worsening symptoms to non-pulmonary causes, or may be hesitant to add medications due to polypharmacy risk. This represents a systematic under-treatment risk in the most prevalent patient profile.
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Exacerbation Predicts De-escalation, Not Intensification
Contrary to guideline logic and prior studies (e.g. López-Campos 2016), exacerbation was associated with step-downs and complex simultaneous changes, but not with step-ups. This unexpected pattern may reflect the reclassification of treatment regimens post-exacerbation rather than purely reactive intensification — a nuance worth further investigation.
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Diagnostic Quality Is a Persistent Problem
32.6% of patients in the broader study population did not meet spirometric criteria for COPD, yet received diagnoses and treatment adjustments. The omission of spirometry — the only validated confirmatory test for COPD — is a recurring finding across Swiss COPD cohort publications (Jochmann 2010, Urwyler 2019). It introduces misclassification at the foundational level of care.
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GOLD Group C Is Unusually Difficult to Manage
Group C patients (frequent exacerbators, low symptom burden) were associated with all three types of treatment change — step-ups, step-downs, and simultaneous changes. This instability in management may be part of why the 2022/2023 GOLD revision proposed merging Groups C and D into a new Group E, simplifying the treatment pathway for frequent exacerbators regardless of symptom score.