Should pulse oximetry be included in GPs' assessment of patients with obstructive lung disease?

OBJECTIVE: To explore the associations between decreased pulse oximetry values (SpO2) and clinical, laboratory, and demographic variables in general practice patients diagnosed with asthma or chronic obstructive pulmonary disease (COPD), including those with both COPD and asthma in combination. DESIGN/SETTING: A cross-sectional study in seven Norwegian general practices of patients aged 40 years or over who were diagnosed by their general practitioner (GP) with asthma and/or COPD. The patients were examined during a stable phase of their disease. Patients diagnosed with COPD (including those with combined COPD/asthma) and those diagnosed with asthma only were analysed separately. MAIN OUTCOME MEASURES: Decreased SpO2 values (≤ 95% and ≤ 92%). RESULTS: Of 372 patients included (mean age 61.5 years, 62% women), 82 (22.0%) had SpO2 ≤ 95%, of which 11 had SpO2 ≤ 92%. In both asthma and COPD patients, SpO2 ≤ 95% was significantly associated with reduced lung function (spirometry), a diagnosis of coronary heart disease and older age (≥ 65 years). In the COPD group, haemoglobin above normal was associated with SpO2 ≤ 95%. These associations were confirmed by multivariable logistic regression, where FEV1% predicted < 50 was the strongest predictor of SpO2 ≤ 95% (odds ratio 6.8, 95% confidence interval 2.8-16.4). CONCLUSION: Pulse oximetry represents a useful diagnostic adjunct for assessing the severity of obstructive pulmonary disease. Decreased pulse oximetry values in stable-phase patients with asthma and/or COPD should prompt the GP to consider revising the diagnosis and treatment and to look for co-morbidities. Key Points Despite its common use in general practice, the diagnostic benefits of pulse oximetry remain to be established. Decreased pulse oximetry values are associated with both reduced lung function (spirometry) and with a diagnosis of coronary heart disease. Decreased pulse oximetry values may reflect suboptimal treatment and/or undiagnosed comorbidity. Pulse oximetry may therefore be a useful measure in the follow-up of asthma and COPD patients in general practice.

Changed terms for drug payment influenced GPs' diagnoses and prescribing practice for inhaled corticosteroids.

BACKGROUND: Inhaled glucocorticosteroids (ICS) are first-line anti-inflammatory treatment in asthma, but not in chronic obstructive pulmonary disease (COPD). To restrict ICS use in COPD to cases of severe disease, new terms for reimbursement of drug costs were introduced in Norway in 2006, requiring a diagnosis of COPD to be verified by spirometry. OBJECTIVES: To describe how GPs' diagnoses and treatment of patients who used ICS before 2006 changed after a reassessment of the patients that included spirometry. METHODS: From the shared electronic patient record system in one group practice, patients ≥ 50 years prescribed ICS (including in combination with long-acting beta2-agonists) during the previous year were identified and invited to a tailored consultation including spirometry to assure the quality of diagnosis and treatment. GPs' diagnoses and ICS prescribing patterns after this reassessment were recorded, retrospectively. RESULTS: Of 164 patients identified, 112 were included. Post-bronchodilator spirometry showed airflow limitation indicating COPD in 55 patients. Of the 57 remaining patients, five had a positive reversibility test. The number of patients diagnosed with asthma increased (from 25 to 62) after the reassessment. A diagnosis of COPD was also more frequently used, whereas fewer patients had other pulmonary diagnoses. ICS was discontinued in 31 patients; 20 with mild to moderate COPD and 11 with normal spirometry. CONCLUSION: Altered reimbursement terms for ICS changed GPs' diagnostic practice in a way that made the diagnoses better fit with the treatment given, but over-diagnosis of asthma could not be excluded. Spirometry was useful for identifying ICS overuse.

Asthma, chronic obstructive pulmonary disease, or both? Diagnostic labeling and spirometry in primary care patients aged 40 years or more.

AIMS: To describe symptoms and lung function in patients registered with asthma or chronic obstructive pulmonary disease (COPD) in primary care and to examine how spirometry findings fit with general practitioners' (GPs) diagnoses. METHODS: Patients aged ≥40 years with a diagnosis of asthma or COPD registered in the electronic medical record during the previous 5 years were recruited at seven GP offices in Norway in 2009-2010. Registered diagnosis, spirometry results, comorbidity, and reported symptoms were compared. RESULTS: Among 376 patients, 62% were women. Based on Global Initiative for Chronic Obstructive Lung Diseases criteria, a spirometry diagnosis of COPD could be made in 68.1% of the patients with a previous COPD diagnosis and in 17.1% of those diagnosed with asthma only (P < 0.001). The κ agreement between last clinical diagnosis of COPD and COPD based on spirometry was 0.50. A restrictive spirometry pattern was found in 19.4% and more frequently in patients diagnosed with both asthma and COPD (23.9%) than in patients diagnosed with COPD only (6.8%, P = 0.003). CONCLUSION: The ability of GPs to differentiate between asthma and COPD seems to have considerably improved during the last decade, probably due to the dissemination of spirometry and guidelines for COPD diagnosis. A diagnosis of COPD that cannot be confirmed by spirometry represents a challenge in clinical practice, in particular when a restrictive pattern on spirometry is found.