Joke Grootens

Current clinical guideline definitions of airflow obstruction and COPD overdiagnosis in primary care

The aim of the present study was to establish the agreement between two recommended definitions of airflow obstruction in symptomatic adults referred for spirometry by their general practitioner, and investigate how rates of airflow obstruction change when pre-bronchodilator instead of post-bronchodilator spirometry is performed. The diagnostic spirometric results of 14,056 adults with respiratory obstruction were analysed. Differences in interpretation between a fixed 0.70 forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) cut-off point and a sex- and age-specific lower limit of normal cut-off point for this ratio were investigated. Of the subjects, 53% were female and 69% were current or ex-smokers. The mean post-bronchodilator FEV1/FVC was 0.73 in males and 0.78 in females. The sensitivity of the fixed relative to the lower limit of normal cut-off point definition was 97.9%, with a specificity of 91.2%, positive predictive value of 72.0% and negative predictive value of 99.5%. For the subgroup of current or ex-smokers aged ≥50 yrs, these values were 100, 82.0, 69.2 and 100%, respectively. The proportion of false positive diagnoses using the fixed cut-off point increased with age. The positive predictive value of pre-bronchodilator airflow obstruction was 74.7% among current or ex-smokers aged ≥50 yrs. The current clinical guideline-recommended fixed 0.70 forced expiratory volume in one second/forced vital capacity cut-off point leads to substantial overdiagnosis of obstruction in middle-aged and elderly patients in primary care. Using pre-bronchodilator spirometry leads to a high rate of false positive interpretations of obstruction in primary care.

Diagnostic accuracy of pre-bronchodilator FEV1/FEV6 from microspirometry to detect airflow obstruction in primary care: a randomised cross-sectional study

Background:Forced expiratory volume in 1s/forced expiratory volume in 6 s ( FEV1/FEV6) assessment with a microspirometer may be useful in the diagnostic work up of subjects who are suspected of having COPD in primary care.Aim:To determine the diagnostic accuracy of a negative pre-bronchodilator (BD) microspirometry test relative to a full diagnostic spirometry test in subjects in whom general practitioners (GPs) suspect airflow obstruction.Methods:Cross-sectional study in which the order of microspirometry and diagnostic spirometry tests was randomised. Study subjects were (ex-)smokers aged ⩾50 years referred for diagnostic spirometry to a primary care diagnostic centre by their GPs. A pre-BD FEV1/FEV6 value <0.73 as measured with the PiKo-6 microspirometer was compared with a post-BD FEV1/FVC (forced vital capacity) <0.70 and FEV1/FVC<lower limit of normal (LLN) from diagnostic spirometry.Results:One hundred and four subjects were analysed (59.6% males, 42.3% current smokers). Negative predictive values from microspirometry for airflow obstruction based on the fixed and LLN cut-off points were 94.4% (95% confidence interval (CI), 86.4–98.5) and 96.3% (95% CI, 88.2–99.3), respectively. In all, 18% of positive microspirometry results were not confirmed by a post-BD FEV1/FVC <0.70 and 44% of tests were false positive compared with the LLN criterion for airflow obstruction.Conclusions:Pre-bronchodilator microspirometry seems to be able to reliably preselect patients for further assessment of airflow obstruction by means of regular diagnostic spirometry. However, use of microspirometry alone would result in overestimation of airflow obstruction and should not replace regular spirometry when diagnosing COPD in primary care.

Tracing uncontrolled asthma in family practice using a mailed asthma control questionnaire

PURPOSE A substantial proportion of adult patients with asthma have inadequately controlled symptoms despite the availability of effective treatment. The Asthma Control Questionnaire (ACQ) can be used to discriminate between asthma patients with well- and suboptimally controlled asthma symptoms. The objective of this study was to investigate whether a postal mailing of the ACQ can be used to identify asthma patients with suboptimal symptom control in family practice. METHODS In this observational study, we sent 434 asthma patients from 6 Dutch family practices an ACQ by mail to measure control of their asthma symptoms. Both respondents and nonrespondents were characterized by information gathered from their medical records. Patients with an ACQ sum score (total score) of greater than 3 were considered to have suboptimally controlled asthma symptoms. RESULTS The response rate was 77%. Respondents were more likely than non-respondents to be female and to use asthma medication. The mean ACQ sum score of the respondents was 5.2. Of this group, 53.4% (95% confidence interval, 48.0%–58.8%) had suboptimally controlled asthma symptoms. Of the 168 respondents who had not visited their family physician in the 2 years before the study, 42.9% (95% confidence interval, 35.4%–50.4%) had inadequate asthma symptom control. CONCLUSIONS Our results show that a postal mailing of the ACQ is an effective approach for tracing asthma patients who need medical attention. It also traces patients who would otherwise not have consulted their family physician. The ACQ seems to be a useful starting point for health care professionals in family practice to improve the level of asthma symptom control in their patient population.

Should the diagnosis of COPD be based on a single spirometry test

Clinical guidelines indicate that a chronic obstructive pulmonary disease (COPD) diagnosis is made from a single spirometry test. However, long-term stability of diagnosis based on forced expiratory volume in 1 s over forced vital capacity (FEV1/FVC) ratio has not been reported. In primary care subjects at risk for COPD, we investigated shifts in diagnostic category (obstructed/non-obstructed). The data were from symptomatic 40+ years (ex-)smokers referred for diagnostic spirometry, with three spirometry tests, each 12±2 months apart. The obstruction was based on post-bronchodilator FEV1/FVC < lower limit of normal (LLN) and <0.70 (fixed ratio). A total of 2,352 subjects (54% male, post-bronchodilator FEV1 76.5% predicted) were studied. By LLN definition, 32.2% were obstructed at baseline, but 32.2% of them were no longer obstructed at years 1 and/or 2. By fixed ratio, these figures were 46.6 and 23.8%, respectively. Overall, 14.3% of subjects changed diagnostic category by 1 year and 15.4% by 2 years when applying the LLN cut-off, and 15.1 and 14.6% by fixed ratio. Change from obstructed to non-obstructed was more likely for patients with higher body mass index (BMI) and baseline short-acting bronchodilator (SABA) users, and less likely for older subjects, those with lower FEV1% predicted, baseline inhaled steroid users, and current smokers or SABA users at year 1. Change from non-obstructed to obstructed was more likely for males, older subjects, current smokers and patients with lower baseline FEV1% predicted, and less likely for those with higher baseline BMI. Up to one-third of symptomatic (ex-)smokers with baseline obstruction on diagnostic spirometry had shifted to non-obstructed when routinely re-tested after 1 or 2 years. Given the implications for patients and health systems of a diagnosis of COPD, it should not be based on a single spirometry test.

Bronchodilation and smoking interaction in COPD: a cohort pilot study to assess cardiovascular risk.

Background: Smoking and bronchodilator treatment are both extensively studied as key elements in patients with chronic obstructive pulmonary disease. However, little is known about whether or not these elements interact in terms of developing cardiovascular diseases in patients with COPD. Objectives: To explore to what extent the risk of developing ischemic cardiovascular disease in COPD patients is mediated by smoking status, use of bronchodilators and – specifically – their interaction. Methods: We performed an observational pilot study on a relatively healthy Dutch COPD cohort from a primary care diagnostic center database with full information on spirometry tests, smoking status, bronchodilator use and other prescribed medication. We defined first ischemic cardiovascular events as primary outcome, measured by first prescription of antiplatelet drugs and/or nitrates. Unadjusted analyses by Kaplan-Meier were followed by adjusted Cox’ proportional hazards. Results: 845 COPD patients, totaling 2,169 observation years, were included in the analyses. We observed an increased risk for nonfatal ischemic cardiovascular events by smoking (adjusted HR = 3.58, p = 0.001) and a protective effect of bronchodilators (adjusted HR = 0.43, p = 0.01). Although the protective effect of bronchodilators appears to be substantially minimized in patients that persist in smoking, we could not statistically confirm a hazardous interaction between bronchodilators and smoking (HR 2.50, p = 0.21). Conclusion: Our study reveals bronchodilators may protect from ischemic cardiovascular events in a relatively ‘healthy’ COPD population. We did not confirm a hazardous interaction between bronchodilators and smoking, although we observed current smokers benefit substantially less from the protective effect of bronchodilators.

Point of care microspirometry to facilitate the COPD diagnostic process in primary care: a clustered randomised trial

We studied if pre-bronchodilator FEV1/FEV6 determinations with microspirometers by GPs improve the diagnostic process for COPD in a 6–8 month clustered randomised controlled trial in Dutch general practices (http://www.trialregister.nl: NTR4041). GPs allocated to microspirometry (MI) used COPD-6® microspirometers in patients ≥50 years old with a smoking history and respiratory complaints that could indicate undiagnosed COPD and ask to refer patients for full spirometry if MI was positive (FEV1/FEV6 <0.73). Introduction of the COPD-6® was postponed in the usual care (UC) group. GPs of both study arms were asked to list all patients that fulfilled study criteria and at the end of the study we screened the electronic medical record system for number of patients that fulfilled study criteria and visited their GP within the study period. Main end point was a documented diagnostic conclusion of COPD within 3 months after the patient’s visit. We used multilevel logistic regression with correction for relevant covariates. Next, we described the process of care. 21 practices (88 GPs) participated and 416 possible undiagnosed COPD patient visited these practices in the study period. 78 (of 192 visiting) subjects were listed by MI GPs and diagnostic conclusions were documented in 77%, compared to 61 listed (of 224 visiting) subjects and 44% with documented diagnostic conclusions by UC GPs (Odds Ratio: OR: 4.3, 95%CI: 1.6–11.5). Microspirometry improved the diagnostic process for possible underlying COPD in patients who consulted their GP with respiratory symptoms, but the majority of possible undiagnosed COPD patients remained unrecognised by GPs.Chronic lung disease: Quick test may help identify potential sufferersA quick, simple test that can be used by family doctors may help identify patients suffering from chronic obstructive pulmonary disease (COPD). The small, inexpensive microspirometry (MI) kit enables doctors conducting routine appointments to measure the volume of air expelled from patients’ lungs. Lisette van den Bemt at Radboud University Medical Center, the Netherlands, and co-workers worked with two groups of doctors in local practices. Both groups were asked to identify patients over 50 with a smoking history, respiratory problems and no diagnose of asthma and COPD, and start a diagnostic process for COPD. One group was given microspirometers to aid diagnoses. Of 192 patients visiting the MI doctors, 78 were identified and 77 per cent were later listed as COPD or COPD was ruled out. In the other group, 61 out of 224 patients were identified with only 44 per cent listed.

Kan de diagnose COPD op één spirometrietest berusten

SamenvattingSchermer TR, Robberts B, Grootens J, Lucas A, Thoonen BP, Smeele IJ. Kan de diagnose COPD op één spirometrietest berusten? Huisarts Wet 2017;60(10):497-9. Huisartsen stellen de diagnose COPD vaak op basis van één spirometrietest. Een te lage post-bronchodilatoire FEV1/FVC wijst dan op een luchtwegobstructie die kan passen bij COPD. In een onderzoek onder 2352 personen met verdenking op COPD, die door hun huisarts waren verwezen naar huisartsenlaboratoria, bleken aanvankelijk 758 personen (32%) luchtwegobstructie te vertonen. Na een jaar was dit bij 22% (168/758) en na twee jaar bij 32% (244/758) echter niet meer het geval. Van de 1594 personen zonder obstructie bij de eerste spirometrietest was na een jaar bij 90% wederom geen sprake van obstructie; na twee jaar bij 85%. Verschillende persoonskenmerken voorspelden de kans op verschuiving van obstructief naar niet-obstructief. De FEV1/FVC en het daarop gebaseerde oordeel wel/niet obstructief varieert dusdanig in de tijd dat eenmalige spirometrie leidt tot over- en onderdiagnostiek van COPD.