Diagnosing asthma in general practice with portable exhaled nitric oxide measurement--results of a prospective diagnostic study: FENO < or = 16 ppb better than FENO < or =12 ppb to rule out mild and moderate to severe asthma [added].

BACKGROUND: To evaluate the sensitivity, specificity and predictive values of fractional exhaled nitric oxide (FENO) for the diagnosis of asthma in general practice. METHODS: Prospective diagnostic study with 160 patients attending 10 general practices for the first time with complaints suspicious of obstructive airway disease (OAD). Patients were referred to a lung function laboratory for diagnostic investigation. The index test was FENO measured with a portable FENO analyser based on electrochemical sensor. The reference standard was the Tiffeneau ratio (FEV1/VC) as received by spirometric manoeuvre and/or results of bronchial provocation. Bronchial provocation with methacholine was performed to determine bronchial hyper-responsiveness (BHR) in the event of inconclusive spirometric results. RESULTS: 88 (55%) were female; their average age was 43.9 years. 75 (46.9%) patients had asthma, 25 (15.6%) had COPD, 8 (5.0%) had an overlap of COPD and asthma, and 52 (32.5%) had no OAD. At a cut-off level of 46 parts per billion (ppb) (n = 30; 18.8%), sensitivity was 32% (95%CI 23-43%), specificity 93% (95%CI 85-97%), positive predictive value (PPV) 80% (95%CI 63-91%), negative predictive value (NPV) 61% (95%CI 52-69%) when compared with a 20% fall in FEV1 from the baseline value (PC20) after inhaling methacholine concentration 46 ppb. Mild and moderate to severe asthma could be ruled out with FENO

Diagnostic accuracy of spirometry in primary care.

BACKGROUND: To evaluate the sensitivity, specificity and predictive values of spirometry for the diagnosis of chronic obstructive pulmonary disease (COPD) and asthma in patients suspected of suffering from an obstructive airway disease (OAD) in primary care. METHODS: Cross sectional diagnostic study of 219 adult patients attending 10 general practices for the first time with complaints suspicious for OAD. All patients underwent spirometry and structured medical histories were documented. All patients received whole-body plethysmography (WBP) in a lung function laboratory. The reference standard was the Tiffeneau ratio (FEV1/VC) received by the spirometric maneuver during examination with WBP. In the event of inconclusive results, bronchial provocation was performed to determine bronchial hyper-responsiveness (BHR). Asthma was defined as a PC20 fall after inhaling methacholine concentration < or = 16 mg/ml. RESULTS: 90 (41.1%) patients suffered from asthma, 50 (22.8%) suffered from COPD, 79 (36.1%) had no OAD. The sensitivity for diagnosing airway obstruction in COPD was 92% (95%CI 80-97); specificity was 84% (95%CI 77-89). The positive predictive value (PPV) was 63% (95%CI 51-73); negative predictive value (NPV) was 97% (95%CI 93-99). The sensitivity for diagnosing airway obstruction in asthma was 29% (95%CI 21-39); specificity was 90% (95%CI 81-95). PPV was 77% (95%CI 60-88); NPV was 53% (95%CI 45-61). CONCLUSION: COPD can be estimated with high diagnostic accuracy using spirometry. It is also possible to rule in asthma with spirometry. However, asthma can not be ruled out only using spirometry. This diagnostic uncertainty leads to an overestimation of asthma presence. Patients with inconclusive spirometric results should be referred for nitric oxide (NO) - measurement and/or bronchial provocation if possible to guarantee accurate diagnosis.

Depression and panic disorder as predictors of health outcomes for patients with asthma in primary care.

INTRODUCTION: Depression and panic disorder are widely acknowledged as complicating factors in asthma patients. However, their impact on health outcomes in primary care patients is less well examined. This study prospectively evaluated the impact of depression and panic disorder on outcomes of primary care patients with asthma over 1 year. METHODS: At baseline, 256 asthma patients from 43 primary care practices completed self-report questionnaires including the Patient Health Questionnaire (PHQ), the Asthma Quality of Life Questionnaire (AQLQ), and a structured questionnaire evaluating asthma severity, hospitalisation and emergency visits. One year later, 185 (72.3%) patients completed the same questionnaire. RESULTS: At baseline, 3.9% of patients suffered from major depressive disorder, 22.7% from minor depressive disorder, and 7.8% from panic disorder. In the year under evaluation, 17 patients (9.2%) received emergency home visits and 10 patients (5.4%) were admitted to a hospital. Depression at baseline predicted hospitalisation within the subsequent year (OR 6.1; 95% CI 1.5-24.6) and panic disorder predicted unscheduled emergency home visits (OR 4.8; 95% CI 1.3-17.7). Depression but not panic disorder predicted the AQLQ scales activity (p=0.001), symptoms (p=0.001), emotions (p=0.001) and environment (p=0.001) at follow-up. CONCLUSIONS: Although rates of hospitalisation and emergency visits in primary care are low, the impact of psychiatric comorbidity on health outcomes for patients with asthma is substantial. It might be helpful to identify patients with psychiatric comorbidity by analysing reasons for hospitalisation and emergency visits. For these patients, intensifying care with psychiatric interventions might help to reduce inappropriate healthcare utilisation and avoid adverse outcomes.

Asthma patients with low perceived burden of illness: a challenge for guideline adherence.

RATIONALE AND AIMS: The reason why many patients seem to tolerate suffering from sub-optimal treated asthma remains unclear. The aim was to evaluate the guideline adherence combined with quality of life of patients with moderate to severe asthma. METHODS: 256 asthma patients from 43 primary care practices in Saxony-Anhalt filled in a questionnaire including the Asthma Quality of Life Questionnaire (AQLQ), the Patient Health Questionnaire (PHQ-D) and questions evaluating the asthma severity, medication and self-management. RESULTS: 43.4% suffered from moderate to severe asthma. Drug treatment accorded with guidelines in 36.9%, drug dosage of inhaled steroids was too low in 34.3%, and 21.5% were not treated according to guidelines. A total of 7.3% of the patients received end-of-dose therapy. AQLQ declined and depression rose with asthma severity and guideline non-adherence (P < 0.001). Only 29.1% received asthma education. However, 64.5% of the patients without education did not want to receive education. They had a higher quality of life, lower depression (P < 0.001) and lower use of steroids (P = 0.016). Higher depression scores where related with hospital admission (OR 3.29; 95% CI 1.57-6.87 for each quartile of PHQ-D) and unscheduled home visits or ambulatory care (OR 1.58; 1.07-2.33). CONCLUSION: There is a large variation of asthma severity which can partly be explained by the guideline adherence of medication and deficits of patients' management. The perceived burden of illness plays a more important role for education and self-management than the real severity of disease. Therefore, target-oriented interventions are needed to identify and motivate patients at risk.

Is serial determination of inspiratory muscle strength a useful prognostic marker in chronic heart failure?

BACKGROUND: Little data exists on the prognostic role of inspiratory muscle strength (PImax) in chronic heart failure (CHF). Training studies, however, frequently use it as a therapeutic target and surrogate marker for prognosis. The prognostic value of changes of PImax that allow this extrapolation is unknown. DESIGN: Patients with stable CHF were prospectively included and 1-year and all-time event rates recorded for endpoint analysis. METHODS: In 158 patients (85% men; New York Heart Association functional class: 2.4+/-0.6), PImax was measured along with clinical evaluations at two visits, the initial visit and the second visit, 6.4+/-1.4 months apart. The mean follow-up was 59+/-34 months. RESULTS: Overall, 59 patients (37%) reached the primary endpoint of death or hospitalization (endpoint positive), and overall mortality rate (secondary endpoint) was 26% (42 patients). PImax did not differ between endpoint-negative and endpoint-positive patients, both at the initial and at the second visit (8.3+/-5.6 vs. 7.3+/-3.4 kPa and 8.8+/-6.0 vs. 7.9+/-3.6 kPa, respectively; P=NS), and both groups showed increased PImax (0.6+/-2.6 vs. 0.6+/-2.8 kPa; P=NS). Cox analyses found neither the absolute nor the relative change of PImax to be significant predictors for the primary and secondary endpoints (P=NS for both), both for the 1-year and for the all-time event rates. Endpoint rates did not differ between patients showing increasing or decreasing PImax (P=NS; relative risk (RR): 0.77; 95% confidence interval: 0.47-1.27). CONCLUSION: Trials focusing on inspiratory muscle function should use the actual levels of PImax as a surrogate marker to represent prognostic information, rather than relative or absolute changes. This is the first study to investigate the prognostic information of the changes of PImax over time, regarding both short-term and long-term morbidity and mortality in patients with stable CHF.