Interpreting lung oscillometry results: Z-scores or fixed cut-off values?

Instead of using % predicted values or Z-scores to define and quantify respiratory abnormality in oscillometry, fixed cut-off values will likely give more accurate discrimination https://bit.ly/3vVmIyE.

Is underuse of Inhaled Corticosteroids for Asthma in India contributing to 42% of global asthma deaths?

Background: : According to the 2019 Global Burden of Disease (GBD) report, India contributes to an estimated 12.9% of global asthma cases (34.3 million) but a disproportionate 42.3% of all global asthma deaths. Also, asthma causes 4.83 million disability-adjusted life years (DALYs) annually in India, four times more than China, which ranks second. Hypothesis: : We hypothesised that this disproportionate increase in asthma deaths and suffering in India could be due to the under-use of inhaled corticosteroids. Methods: : Using the estimated number of asthma cases in each state and union territory in India (34.3 million) from the 2019 GBD data, we calculated the expected sales of inhaled corticosteroids (ICS) for asthmatics in India. We assumed that 10% of asthmatics have mild intermitted disease and thus need only 4 units of ICS pMDI per year. The remaining 90% should ideally use 12 units of ICS pMDI or equivalent DPI. We also assumed that 30% of ICS sales in India would be accounted for by the 38 million COPD patients. State-wise actual sales of ICS in India were obtained from IQVIA. Results: : The total amount of ICS sales in India for asthma obtained from IQVIA was 26.4 million versus the 384.16 million expected sales, which is only 6.8% of the required estimated sales. Moreover, when we correlated state-wise actual sales of ICS in India versus asthma mortality and DALYs (per 100,000 population), we found a significant negative correlation (R = -0.56; P < 0.001 for asthma deaths and R = -0.61; P < 0.001 for asthma DALYs). Impact and Future Direction: : Policy-makers, health care providers, public health researchers, asthma sufferers and the people at large need to take cognizance of our findings and undertake appropriate measures, such as creating awareness and ensuring availability and regular use of ICS by asthmatics in India.

Predictors for detecting chronic respiratory diseases in community surveys: A pilot cross-sectional survey in four South and South East Asian low- and middle-income countries.

BACKGROUND: Our previous scoping review revealed limitations and inconsistencies in population surveys of chronic respiratory disease. Informed by this review, we piloted a cross-sectional survey of adults in four South/South-East Asian low-and middle-income countries (LMICs) to assess survey feasibility and identify variables that predicted asthma or chronic obstructive pulmonary disease (COPD). METHODS: We administered relevant translations of the BOLD-1 questionnaire with additional questions from ECRHS-II, performed spirometry and arranged specialist clinical review for a sub-group to confirm the diagnosis. Using random sampling, we piloted a community-based survey at five sites in four LMICs and noted any practical barriers to conducting the survey. Three clinicians independently used information from questionnaires, spirometry and specialist reviews, and reached consensus on a clinical diagnosis. We used lasso regression to identify variables that predicted the clinical diagnoses and attempted to develop an algorithm for detecting asthma and COPD. RESULTS: Of 508 participants, 55.9% reported one or more chronic respiratory symptoms. The prevalence of asthma was 16.3%; COPD 4.5%; and 'other chronic respiratory disease' 3.0%. Based on consensus categorisation (n = 483 complete records), "Wheezing in last 12 months" and "Waking up with a feeling of tightness" were the strongest predictors for asthma. For COPD, age and spirometry results were the strongest predictors. Practical challenges included logistics (participant recruitment; researcher safety); misinterpretation of questions due to local dialects; and assuring quality spirometry in the field. CONCLUSION: Detecting asthma in population surveys relies on symptoms and history. In contrast, spirometry and age were the best predictors of COPD. Logistical, language and spirometry-related challenges need to be addressed.

Association between air pollution, body mass index, respiratory symptoms, and asthma among adolescent school children living in Delhi, India.

BACKGROUND: Delhi is one of the most polluted cities in the world with annual average ambient PM10 and PM2.5 levels exceeding the World Health Organization standards by over 15 fold. We aimed to study the prevalence of respiratory and allergic symptoms and asthma among adolescent children living in Delhi (D) and compare it with children living in lesser polluted cities of Kottayam (K) and Mysore (M) located in Southern India. METHODS: 4361 boys and girls between the age group of 13-14 and 16-17 years from 12 randomly selected private schools from D, K, and M were invited to participate. Modified and expanded International Study for Asthma and Allergies in Children (ISAAC) questionnaires (Q) were filled by the students who also performed spirometry using the ultrasonic flow-sensor-based nDD Spirometer. RESULTS: 3157 students (50.4% boys) completed the Q and performed good quality spirometry. The prevalence of asthma and airflow obstruction among children living in Delhi was 21.7% using the ISAAC Q and 29.4% on spirometry, respectively. This was accompanied by significantly higher rates of self-reported cough, shortness of breath, chest tightness, sneezing, itchy and watery eyes, itchy skin, and eczema among Delhi children (vs. K-M, all P < 0.05). Delhi children were more overweight and obese (39.8% vs. 16.4%, P < 0.0001), and this was the only risk factor that was strongly associated with asthma (odds ratio [OR]: 1.79; confidence interval: 1.49-2.14), with a more pronounced effect in Delhi children (P = 0.04). Forced expiratory volume1 and Forced vital capacity values were significantly higher in Delhi children (vs. K-M P < 0.0001). Preserved ratio impaired spirometry was more common in K-M children (P < 0.0001). CONCLUSION: Adolescent children living in the polluted city of Delhi had a high prevalence of asthma, respiratory symptoms, allergic rhinitis, and eczema that was strongly associated with a high body mass index (BMI). Our study suggests an association between air pollution, high BMI, and asthma/allergic diseases, which needs to be explored further.

COPD awareness in the urban slums and rural areas around Pune city in India.

COPD is the second leading cause of death and disability adjusted life years (DALYs) in India, yet, it remains poorly recognized. We aimed to study the level of awareness of COPD in urban slums of Pune city in India and its neighboring rural areas. All male and female subjects above the age of 30 years residing in 13 randomly selected slums of Pune city (total population of 3000) and 7 randomly selected neighboring rural villages (total population of 3000) were invited to participate in this cross-sectional community survey. After obtaining written informed consent, 13 trained community health workers (CHWs) administered a questionnaire that captured their level of awareness of COPD. Of the 6000 subjects approached, 5420 residents (mean age ± SD = 48.0 ± 13.5 years; 38% males) consented and answered all questions. The number of people who had ever heard the word COPD was 49/5420 [0.9% (0.6-1.1%); 0.7% (0.5-1.3%) of the urban slum dwellers and 1.15% (0.5-1.3%) of rural residents]. Among those who had never heard the word COPD (n = 5371), when asked what was the name of the disease caused by long-term tobacco smoking, 38% said cancer, 16.7% said asthma, and 4.4% said TB. Among those who had heard the word COPD (n = 49), 6.1% said it was a disease of the heart, and 61% attributed COPD to smoke and dust pollution and 20% to tobacco smoking. The level of awareness of COPD in the Indian community is extremely low, highlighting the need to have nationwide mass awareness programs in India.

Normal spirometry predictive values for the Western Indian adult population.

Interpretation of spirometry involves comparing lung function parameters with predicted values to determine the presence/severity of the disease. The Global Lung Function Initiative (GLI) derived reference equations for healthy individuals aged 3-95 years from multiple populations but highlighted India as a "particular group" for whom further data are needed. We aimed to derive predictive equations for spirometry in a rural Western Indian adult population.We used spirometry data previously collected (2008-2012) from 1258 healthy adults (aged 18 years and over) by the Vadu Health and Demographic Surveillance System. We constructed sex-stratified prediction equations for forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and FEV1/FVC using the Generalised Additive Model for Location, Scale and Shape (GAMLSS) method to derive the best fitting model of each outcome as a function of age and height.When compared with GLI Ethnicity Codes 1 (White Caucasian) and 5 (Other/Mixed), the Western Indian adult population appears to have lower lung volumes on average, though the FEV1/FVC ratio is comparable. Both age and height were predictive of mean FEV1 and FVC; and for females, the variability of response was also dependent on age. FEV1/FVC appears to have a very strong age effect, highlighting the limitations of using a fixed 0.7 cut-off value.The use of GLI normal values may result in overdiagnosis of lung disease in this population. We recommend that the values and equations generated from this study should be used by physicians in their routine practice for diagnosing disease and its severity in adults from the Western Indian population.