Effect of particulate matter on continuous positive airway pressure adherence in obstructive sleep apnea patients

Background

Sleep quality could be affected by air pollution, especially for particulate matter with a diameter of less than 10 microns (PM10) and particulate matter with a diameter of less than 2.5 microns (PM2.5). However, no direct study demonstrates the relationship and impact of air pollution especially PM10 and PM2.5 on continuous positive airway pressure (CPAP) adherence. Thus, we aimed to study the correlation between PM10, PM2.5, and low CPAP adherence in subjects with obstructive sleep apnea (OSA).

Methods

We conducted a time-series study from August 2016 to May 2022 in Chiang Mai, Thailand. The data from 2,686 visits of CPAP compliance records from 839 OSA patients' electronic medical records at the Sleep Disorders Center, Center of Medical Excellence, Chiang Mai University, Chiang Mai, Thailand were reviewed. The level of adherence was determined utilizing the provided data. Low CPAP adherence was defined as using CPAP for less than 240 minutes per night or less than 70% of nights (i.e., <5 nights/week) in the previous month. The correlation between the monthly average of PM10 and PM2.5 and the rate of low CPAP adherence was analyzed using generalized linear mixed model (GLMM) after adjustment for confounding factors.

Results

There was no effect of an increase in PM10 and PM2.5 on low CPAP adherence [adjusted risk ratio (RR) =0.97; 95% confidence interval (CI): 0.87, 1.09; P value =0.624 and adjusted RR =0.93; 95% CI: 0.81, 1.08; P value =0.350 for PM10 and PM2.5, respectively].

Conclusions

There was no effect of particulate matter on CPAP adherence in OSA patients.

The validity and reliability of the Thai version of the asthma control test

BACKGROUND

The Asthma Control Test (ACT) has been widely used for the assessment of asthma control. However, it has never been validated in adult Thai asthmatic patients.

OBJECTIVE

To determine the validity and reliability of the Thai version of the ACT in adult Thai asthmatic patients.

METHODS

Any correlation between ACT and level of asthma controlled was determined using the Spearman's rank correlation coefficient. The ACT was carried out at 2 visits to a physician (4-12 weeks apart) to ascertain the level of reliability. Discriminant validity was determined using an area under receiver operating characteristic curve (AuROC) to identify the optimum cut-off point of the levels of control.

RESULTS

Seventy-one asthmatic adult patients, 40 (56.3%) female with a mean age of 54.2 ± 14.7 years were enrolled. The Thai version of ACT showed an acceptable internal consistency reliability with a Cronbach's alpha = 0.75. Test-retest reliability was 0.82. There was a significant correlation between the ACT scores and GINA symptom control tool (r = 0.87, p < 0.001). An ACT ≤ 22 was used to screen "not well-controlled" asthma with a sensitivity of 96.4% and specificity of 93.0% and an ACT score ≤ 19 was used to screen "uncontrolled" asthma.

CONCLUSIONS

The Thai version of ACT is valid and a reliable tool for use in adult Thai asthmatic patients. However, the cut off points of ACT for levels of control should be changed to 22 and 19 for differentiation between well vs. partly controlled and partly vs. uncontrolled asthma, respectively.

The National Early Warning Score 2 with Age and Body Mass Index (NEWS2 Plus) to Determine Patients with Severe COVID-19 Pneumonia

(1) Background: Early identification of severe coronavirus disease 2019 (COVID-19) pneumonia at the initial phase of hospitalization is very crucial. To address this, we validated and updated the National Early Warning Score 2 (NEWS2) for this purpose. (2) Methods: We conducted a study on adult patients with COVID-19 infection in Chiang Mai, Thailand, between May 2021 and October 2021. (3) Results: From a total of 725 COVID-19 adult patients, 350 (48.3%) patients suffered severe COVID-19 pneumonia. In determining severe COVID-19 pneumonia, NEWS2 and NEWS2 + Age + BMI (NEWS2 Plus) showed the C-statistic values of 0.798 (95% CI, 0.767-0.830) and 0.821 (95% CI, 0.791-0.850), respectively. The C-statistic values of NEWS2 Plus were significantly improved compared to those of NEWS2 alone (p = 0.012). Utilizing a cut-off point of five, NEWS2 Plus exhibited better sensitivity and negative predictive value than the traditional NEWS2, with values of 99.7% vs. 83.7% and 98.9% vs. 80.7%, respectively. (4) Conclusions: The incorporation of age and BMI into the traditional NEWS2 score enhanced the efficacy of determining severe COVID-19 pneumonia. Physicians can rely on NEWS2 Plus (NEWS2 + Age + BMI) as a more effective decision-making tool for triaging COVID-19 patients during early hospitalization.

Impact of the new European respiratory (ERS)/American Thoracic Society (ATS) pulmonary function test interpretation guidelines 2021 on the interpretation of bronchodilator responsiveness in subjects with airway obstruction

BACKGROUND

The impact of the new 2021 European Respiratory Society (ERS)/American Thoracic Society (ATS) pulmonary function test interpretation guidelines on the interpretation of bronchodilator responsiveness (BDR) in subjects with airway obstruction is still required. Therefore, the objective of this study was to explore the agreement between the 2005 and 2021 ERS/ATS criteria regarding the interpretation of the BDR. Moreover, we explore the factors that influenced the discordance of positive bronchodilator responsiveness (BDR+) between these two criteria.

METHODS

The agreement regarding the interpretation of BDR + between the two criteria was assessed using kappa (κ). The percentage of agreement in the interpretation of BDR + between the two criteria was calculated. The factors that influenced the discordance of BDR + between these two criteria were also analyzed.

RESULTS

A total of 500 subjects with a mean age of 60.5 ± 15.6 years, 62.2% male were included. The study observed a good level of agreement in the interpretation of BDR + between the two criteria with kappa values = 0.782. The percentages of agreement on the interpretation of BDR + between the two criteria were high, with values = 90.6%. Male sex was the only factor that influenced the discordance of BDR + between these two criteria.

CONCLUSION

A good level of agreement was observed in the interpretation of BDR + between the 2005 and 2021 criteria. Therefore, the 2005 and 2021 ERS/ATS criteria for BDR can be used interchangeably. However, the discordance of BDR + between these two criteria could be affected by sex.

Validation of the Pulmonary Embolism Severity Index Risk Classification and the 2019 European Society of Cardiology Risk Stratification in the Southeast Asian Population with Acute Pulmonary Embolism

AIM

To date, no studies representing the Southeast Asian population have validated the Pulmonary Embolism Severity Index (PESI) and 2019 European Society of Cardiology (ESC) risk stratification. Therefore, this study aimed to validate the PESI score, simplified PESI (sPESI), PESI risk classification, and 2019 ESC risk stratification in Southeast Asian patients with acute pulmonary embolism (APE).

METHODS

The present study is a 10-year cross-sectional study. Here, risk regressions were conducted to identify the PESI risk classification, sPESI, and 2019 ESC risk stratification as predictors for 30-day all-cause and PE-related mortalities. Receiver operating characteristic (ROC) curves were constructed to determine the diagnostic ability of the PESI score, sPESI score, PESI risk classification, and 2019 ESC risk stratification to predict 30-day mortality.

RESULTS

A total of 696 patients (male, 286; female, 410; mean age, 57.7±15.7 years) were included in this study from 2011 to 2020. The risk of 30-day all-cause mortality progressively increased with the 2019 ESC risk stratification, being approximately 6-fold higher in the high-risk than in the low-risk class [risk ratio: 6.24 (95% confidence interval (CI), 3.12, 12.47), P＜0.001]. The risk of 30-day all-cause mortality with the PESI risk classification also increased with the risk classes, being approximately 6-fold higher in class V than in class I [adjusted risk ratio: 5.91 (95% CI, 2.25, 15.51), P＜0.001]. The highest area under the receiver operating characteristic curve (AuROC) of the predictive model was the PESI score [AuROC=0.733 (95% CI, 0.685, 0.782)].

CONCLUSION

Our study represents a good validation of the PESI and 2019 ESC risk stratification to predict 30-day mortality after APE diagnosis in the Southeast Asian population.

The long-term impact of COVID-19 pneumonia on pulmonary function and exercise capacity

Background

The sequelae of post-coronavirus disease 2019 (COVID-19) have been widely reported. However, the time point of the follow-up time in the previous studies varied ranging from 3-24 months and the interval time of the follow-up time was too long (6 or 12 months). Thus, a shorter interval time during recovery for assessment of the sequelae of post COVID-19 on lung function and exercise capacity is still required. Therefore, this study aims to explore the long-term impact of COVID-19 pneumonia on pulmonary function and exercise capacity.

Methods

A prospective observational study was conducted on post COVID-19 pneumonia at the Lung Health Center, Division of Pulmonary, Critical Care and Allergy, Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand between May 2021 and April 2022. Spirometry, impulse oscillometry (IOS), and fractional exhaled nitric oxide (FeNO) were assessed at 1-, 6-, 9-, and 12-month post-hospital discharge when compared to healthy controls. The six-minute walk test (6-MWT) was also assessed.

Results

Thirty-eight post COVID-19 pneumonia with ages 41.1±14.8 years (52.6% male) and twenty-five healthy controls were enrolled. The %predicted of forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1) were significantly lower in post COVID-19 pneumonia compared to healthy controls at month 1 and month 9. The improvement of %predicted FVC and FEV1 was observed in post COVID-19 pneumonia. The six-minute walk distance (6-MWD) was significantly lower in post COVID-19 pneumonia compared to healthy controls in all visits, while the 6-MWD improved overtime in post COVID-19 pneumonia.

Conclusions

The long term sequelae of post COVID-19 pneumonia on lung function and exercise capacity were observed. Pulmonary function tests and six-minutes walk test are useful tools for detection of long term sequelae of post COVID-19 pneumonia.

Neutralizing antibody and T-cell responses against SARS-CoV-2 variants by heterologous CoronaVac/ChAdOx-1 vaccination in elderly subjects with chronic obstructive pulmonary disease

BACKGROUND

Data on humoral and cellular immune responses against SARS-CoV-2 after receiving heterologous CoronaVac/ChAdOx-1 (CoVac/ChAd) vaccination in subjects with chronic obstructive pulmonary disease (COPD) are still limited. Therefore, we determined the neutralizing antibody (NAb) and T-cell responses against SARS-CoV-2 wild type (WT) and variants of concern (VOCs) in COPD patients.

METHODS

The levels of NAb as well as specific CD4 and CD8 T-cell responses against SARS-CoV-2 WT and VOCs were determined in COPD patients before and after vaccination.

RESULTS

Four weeks after vaccinations, the median levels of % inhibition of NAb against SARS-CoV-2 WT, Alpha, Beta, and Delta variants were significantly higher compared to pre-vaccination. The induction of NAb against Omicron was very low compared to other variants. At four weeks after vaccination, in comparison to pre-vaccination, the increasing trend of TNF-α-, IFN-γ-, IL-4-, IL-17-, IL-10-, and FasL-producing CD4 T-cells upon stimulation with WT spike peptides were demonstrated. No difference in T-cell responses to spike peptides of Alpha, Beta, and Delta variants and their WT homologs was observed.

CONCLUSION

Heterologous CoVac/ChAd vaccine induced the production of NAb against SARS-CoV-2 WT, Alpha, Beta, and Delta variants, but low for Omicron in COPD patients. Induction of CD4 T-cell subset responses was slightly observed by this vaccine regimen.

CLINICAL TRIALS REGISTRY

This study was approved by the Clinical Trials Registry (Study ID: TCTR20210822002).

Short-term effects of air pollutant exposure on small airway dysfunction, spirometry, health-related quality of life, and inflammatory biomarkers in wildland firefighters: a pilot study

Clinical Trials Registry: Study ID: TCTR20200828005.

Long-Term Impacts of COVID-19 Pneumonia on Quality of Life: A Single Institutional Pilot Study

Many studies have demonstrated poor quality of life (QoL) at 3, 6, 12, and 24 months after coronavirus disease 2019 (COVID-19). However, these studies were limited due to cross-sectional design, a longer gap between visits, and lack of controls for comparison. Therefore, the aim of our prospective study was to assess the impact of COVID-19 pneumonia on QoL in both physical and mental health. A prospective study was conducted on adult patients with COVID-19 pneumonia. We used the 36-Item Short Form Health Survey (SF-36) and Euro Quality of Life-5 Dimensions-5 Levels (EQ-5D-5L), EQ visual analogue scale (EQ-VAS), and Hospital Anxiety and Depression Scale to collect data at months, 1, 3, 6, 9, and 12. Thirty-eight patients with COVID-19 pneumonia and twenty-five healthy subjects were completely followed up on all visits. All domains of SF-36, except bodily pain and EQ-5D-5L of the patients, were lower than controls. There was an improvement of EQ-VAS and SF-36 including physical functioning, social functioning, and role limitation (physical problems) domains throughout study period in the COVID-19 pneumonia group. Adult patients who recovered from COVID-19 pneumonia had lower QoL which improved over the one-year follow-up period.

Factors influencing continuous positive airway pressure adherence in elderly with obstructive sleep apnea

Background

Continuous positive airway pressure (CPAP) is the most effective treatment for symptomatic obstructive sleep apnea (OSA). The identification of actual predictors of CPAP adherence in real-world practice is essential since it enhances more individualized management for the patient. CPAP acceptance and adherence in elderly patients with OSA have the same challenges but the conclusion remains unclear. Therefore, our aim was to explore the factors influencing the adherence of CPAP in elderly OSA patients.

Methods

The retrospective observational study was conducted from OSA patients' computerized medical records at Sleep Disorders Center, Center of Medical Excellence, Chiang Mai University Hospital, Chiang Mai, Thailand between 2018 and 2020. Multivariable risk regression analyses were performed to evaluate the independent factors associated with CPAP non-acceptance and CPAP non-adherence.

Results

Of the 1,070 patients who underwent overnight polysomnography (PSG), 336 (31.4%) were elderly. Of 759 patients who accepted CPAP treatment, 221 (29.1%) were elderly, including 27 (12.2%) non-adherences, 139 (62.9%) adherences and 55 (24.8%) loss follow-up. Elderly patients with adverse attitudes toward CPAP use affected adherence to treatment [adjusted risk ratio (RR) =4.59, 95% CI: 1.79, 11.78, P=0.002]. Female was also associated with low CPAP adherence with adjusted RR =3.10 (95% CI: 1.07, 9.01), P=0.037.

Conclusions

In our largest cohort to date, elderly OSA patients treated with CPAP over long-term follow-ups demonstrated that adherence rates were associated with personal life issues and adverse attitudes towards treatment as well as health problems. Female was also associated with low CPAP adherence. Therefore, in the elderly with OSA, the indication and treatment of CPAP should be customized individually, and if prescribed, regular monitoring to address noncompliance and tolerance should be considered.

Comparative assessment of small airway dysfunction by impulse oscillometry and spirometry in chronic obstructive pulmonary disease and asthma with and without fixed airflow obstruction

Background

Small airways play a major role in the pathogenesis and prognosis of chronic obstructive pulmonary disease (COPD) and asthma. More data on small airway dysfunction (SAD) using spirometry and impulse oscillometry (IOS) in these populations are required. The objective of this study was to compare the two methods, spirometry and IOS, for SAD detection and its prevalence defined by spirometry and IOS in subjects with COPD and asthma with and without fixed airflow obstruction (FAO).

Design

This is a cross-sectional study.

Methods

Spirometric and IOS parameters were compared across four groups (COPD, asthma with FAO, asthma without FAO, and healthy subjects). SAD defined by spirometry and IOS criteria were compared.

Results

A total of 262 subjects (67 COPD, 55 asthma with FAO, 101 asthma without FAO, and 39 healthy controls) were included. The prevalence of SAD defined by using IOS and spirometry criteria was significantly higher in patients with COPD (62.7 and 95.5%), asthma with FAO (63.6 and 98.2%), and asthma without FAO (38.6 and 19.8%) in comparison with healthy control (7.7 and 2.6%). IOS is more sensitive than spirometry in the detection of SAD in asthma without FAO (38.6% vs. 19.8%, p = 0.003) However, in subjects with FAO (COPD and asthma with FAO), spirometry is more sensitive than IOS to detect SAD (95.5% vs. 62.7%, p < 0.001 and 98.2% vs. 63.6%, p < 0.001, respectively).

Conclusion

Small airway dysfunction was significantly detected in COPD and asthma with and without FAO. Although IOS shows more sensitivity than spirometry in the detection of SAD in asthma without FAO, spirometry is more sensitive than IOS in patients with FAO including COPD and asthma with FAO.

Levels and durability of neutralizing antibodies against SARS-CoV-2 Omicron and other variants after ChAdOx-1 or BNT162b2 booster in CoronaVac-primed elderly individuals

The outbreak of the SARS-CoV-2 Omicron variant raised the need for vaccine boosting. We evaluated the efficiency of the third booster vaccine, ChAdOx-1 or BNT162b2, in causing a neutralizing antibody (NAb) response and its durability against the Omicron and other variants in elderly individuals previously vaccinated with 2-dose CoronaVac inactivated vaccine. After receiving 2-dose CoronaVac, only 2.2% of subjects had NAbs against the Omicron variant above the cut-off value. Four weeks after boosting, the number of subjects who had NAb levels above the cut-off values in the ChAdOx-1 and BNT162b2 vaccine boosting groups increased to 41.7% and 54.5%, respectively. However, after 12 and 24 weeks of boosting with any vaccines, NAb levels against the Omicron variant dramatically waned. Twenty-four weeks after boosting, only 2% had high levels of NAbs against the Omicron variant. Compared to other variants, the Omicron variant was less responsive to boosting vaccines. The waning rate of NAb levels for the Omicron variant was much faster than that observed in the Alpha, Beta and Delta variants. To combat the Omicron variant, the fourth booster dose is, therefore, recommended for elderly individuals.

Humoral and cellular immune responses against SARS-CoV-2 variants of concern induced by heterologous CoronaVac/ChAdOx-1 versus homologous ChAdOx-1 vaccination in the elderly

BACKGROUND

The concept of heterologous vaccination against SARS-CoV-2 infection has been adopted in Thailand with limited data on the induction of humoral and cellular immunity, particularly the CoronaVac/ChAdOx-1 (CoVac/ChAd) regimen in the elderly.

OBJECTIVE

In this study, the immune responses of the elderly induced by heterologous CoVac/ChAd and homologous ChAdOx-1 (ChAd/ChAd) vaccinations were demonstrated.

METHODS

A prospective observational study involving healthy participants aged ≥ 60 years who received heterologous CoVac/ChAd or homologous ChAd/ChAd vaccination was conducted. Surrogate neutralizing antibody (NAb) and T-cell responses against the SARS-CoV-2 wild type (WT) and variants of concern were determined at pre and post vaccinations.

RESULTS

At 4 and 12 weeks after heterologous or homologous vaccination, the NAb levels against WT, Alpha, Beta, and Delta variants between each group were not significantly different, except for significant lower NAb against the Beta variant in heterologous group at 12 weeks after vaccination. The NAb against the Omicron at 4 weeks post-vaccination were below the cutoff level for antibody detection in both groups. However, higher spike-specific CD4 T cell producing IFN-γ and TNF-α in the heterologous than the homologous vaccination were observed. Insignificant difference of cellular immune responses to spike-peptides of Alpha, Beta, and Delta variants and their WT homologues was demonstrated.

CONCLUSIONS

In the elderly, heterologous CoVac/ChAd vaccination could induce NAb response against the WT and non-Omicron variants not different from the homologous ChAd/ChAd vaccination. Both regimens could not give adequate NAb of the Omicron strain. The heterologous vaccination, however, induced higher spike-specific Th1 cell response.

Correlation of Air Pollution and Prevalence of Acute Pulmonary Embolism in Northern Thailand

BACKGROUND

The relationship between the level of air pollution and acute pulmonary embolism (APE) has had inconsistent results.

OBJECTIVE

This study aimed to analyze the relationship between the high level of air pollution exposure and APE.

METHODS

A ten-year retrospective cohort, single-center study was performed on patients diagnosed with APE from October 2010 to December 2020. The association between air pollution and monthly APE case diagnosis was analyzed.

RESULTS

A total number of 696 patients was included. The effect of every 10 µg/m³ increment of particulate matters with an aerodynamic diameter < 10 µm (PM₁₀) on total monthly APE cases (unprovoked PE and provoked PE) was increased significantly at lag 4, 5 and 6 months with adjusted RR (95% CI) of 1.06 (1.01, 1.12), p = 0.011, 1.07 (1.01, 1.13), p = 0.021 and 1.06 (1.01, 1.12), p = 0.030, respectively. Adjusted RR for APE was significantly increased for PM₁₀ in the second tertile ((adjusted RR (95% CI) 1.76 (1.12, 2.77)), p = 0.014.

CONCLUSIONS

We conclude that PM₁₀ is associated with an increased prevalence of APE cases. The policy for tighter control of air pollution in our country is needed to reduce the impact of air pollutants on people's health.

Bradycardia and Heart Rate Fluctuation Are Associated with a Prolonged Intensive Care Unit Stay in Patients with Severe COVID-19

Background and Objective: Bradycardia has been observed among patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is suspected to be associated with poorer outcomes. Heart rate (HR) fluctuation has been found to be correlated with a greater mortality rate in critically ill patients. The association of bradycardia and HR fluctuation with the outcome of severe coronavirus disease 2019 (COVID-19) patients has not been clarified. Therefore, we aimed to examine whether bradycardia and HR fluctuation correlated with poor outcomes in patients with severe COVID-19. Materials and Methods: We conducted a secondary analysis from a prospective data collection of patients admitted to the intensive care unit, between April and June 2021, at Chiang Mai University Hospital. Results: The results showed that 62 of 86 patients (72.1%) had bradycardia, defined by HR < 60 beats per minute (bpm). The number of patients with high HR fluctuation, defined as the difference in HR during admission ≥ 40 bpm, was greater among the bradycardia group than in the non-bradycardia group (70.9% vs. 14.7%, p = 0.015, respectively). The patients with bradycardia had greater levels of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). In addition, a greater proportion of patients with bradycardia received interleukin-6 inhibitors and hemoperfusion as a rescue therapy than those with non-bradycardia. After adjusting for age, gender, body mass index, CRP, and mechanical ventilator; bradycardia and the high HR fluctuation were significantly associated with a longer length of stay in the intensive care unit (ICU-LOS), with adjusted risk ratios of 2.67, 95% CI; 1.02, 6.94, p = 0.045 and 2.88, 95% CI; 1.22, 6.78, p = 0.016, respectively. Conclusion: We found that bradycardia and a high heart rate fluctuation were associated with a poorer ICU outcome in terms of longer ICU-LOS among the patients with severe COVID-19.

Neutralizing antibody and T cell responses against SARS-CoV-2 variants of concern following ChAdOx-1 or BNT162b2 boosting in the elderly previously immunized with CoronaVac vaccine

Background

The existence of SARS-CoV-2 variants of concern (VOCs) in association with evidence of breakthrough infections despite vaccination resulted in the need for vaccine boosting. In elderly individuals, information on the immunogenicity of booster vaccinations is limited. In countries where the CoronaVac inactivated vaccine is the primary vaccine, the appropriate boosting regimen is not clear. Immunologic studies of the effects of booster vaccination against VOCs, particularly Delta and Omicron, following CoronaVac in elderly individuals are helpful for policy makers. In this study, we determined the immune responses against VOCs following ChAdOx-1 or BNT162b2 boosting in elderly individuals previously immunized with CoronaVac.

Results

Before boosting, the median % inhibition of neutralizing antibodies (NAbs) against the wild-type (WT), Alpha, Beta, Delta and Omicron variants in the ChAdOx-1 and BNT162b2 groups was 52.8% vs. 53.4, 36.6% vs. 39.9, 5.2% vs. 13.7, 34.3% vs. 44.9, and 20.8% vs. 18.8%, respectively. After boosting with ChAdOx-1 or BNT162b2, the % inhibition of NAbs were increased to 97.3% vs. 97.4, 94.3% vs. 97.3%, 79.9 vs. 93.7, 95.5% vs. 97.5, and 26.9% vs. 31.9% for WT, Alpha, Beta, Delta and Omicron variants, respectively. Boosting with BNT162b2 induced significantly higher NAb levels than boosting with ChAdOx-1 against the Alpha, Beta and Delta variants but not the WT and Omicron variants. NAb levels against Omicron variant were not significantly different before and after boosting with ChAdOx-1 or BNT162b2. To evaluate T-cell responses, S peptides of the WT, Alpha, Beta and Delta variants were used to stimulate T cells. Upon stimulation, the expression of IL-17A in CD8 T cells was higher in the BNT162b2 group than in the ChAdOx-1 boosting group. However, IFN-γ production in CD4 and CD8 T cells did not significantly differ under all vaccination regimens. The expression of FasL in CD4 T cells, but not CD8 T cells, was higher in the BNT162b2-boosted group.

Conclusion

Boosting with either ChAdOx-1 or BNT162b2 in CoronaVac-primed healthy elderly individuals induced high NAb production against all examined VOCs except Omicron. BNT162b2 stimulated higher NAb and some T-cell responses than ChAdOx-1. Vaccine boosting is, therefore, recommended for elderly individuals previously immunized with CoronaVac.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12979-022-00279-8.

The effectiveness of large group demonstration training method on the use of pressurized metered-dose inhaler in elderly with chronic obstructive pulmonary disease

Background

Pressurized metered-dose inhaler (pMDI) is the most commonly used inhaler devices in community hospitals in Thailand. However, the research work on large group demonstration training method in the use of pMDI and pMDI with spacer in cases of chronic obstructive pulmonary disease (COPD) is very limited. Therefore, this study aimed to evaluate the effectiveness of this training method in elderly with COPD patients.

Methods

This prospective cross-sectional study was conducted at COPD clinic, Chiang Dao Hospital, Chiang Mai, Thailand between June 2019 and July 2019. All patients being treated in the clinic were assessed for their inhalation technique and inspiratory flow. After the initial assessment, patients were given instructions regarding the correct inhalation technique of pMDI and pMDI with spacer devices through large group demonstration. One month later, inhalation techniques and inspiratory flow were re-assessed.

Results

A total of 104 COPD patients were included, mean age 70.9±8.3 years, 51 (49.0%) male. At their first visit, 75.0% of pMDI and 81.7% of pMDI with spacer users performed at least one essential step incorrectly. After receiving large group demonstration training, there was a statistically significant increase in all devices; 26.7% vs. 56.7%, P=0.001 for correct technique, 41.7% vs. 62.7%, P=0.026 for appropriate flow, and 11.7% vs. 36.7%, P=0.001 for correct technique and flow.

Conclusions

The provision of large group training significantly increases the correct use of inhalation techniques and inspiratory flow for pMDI and pMDI with spacer in elderly with COPD.

A Real-World Effectiveness of Subcutaneous Immunotherapy on the Cost of Medication, Allergic Rhinitis, and Asthma Exacerbations, as well as Upper Respiratory Tract Infection in Subjects with Allergic Rhinitis with or without Asthma: A Retrospective Pilot Study

Background and Objectives: Real-world studies are limited regarding the effectiveness of SCIT on allergic rhinitis (AR) with and without asthma and the cost of medication in Thailand. Moreover, limited data exist regarding the effectiveness of SCIT on worldwide upper respiratory tract infection (URTI). Therefore, the objective of this study was to compare the medication costs, rate of AR and asthma exacerbations, and rate of URTI in AR with or without asthma subjects before and during three years after receiving the maintenance phase of SCIT, compared with a standard usual care (SUC) group. Materials and Methods: A real-world retrospective study was conducted in AR subjects with or without asthma. From January 2001 to December 2018, 24 subjects with or without asthma received SCIT added to SUC, and 16 subjects were treated with SUC only at the Allergy and Chest Clinic of Chiang Mai Ram Hospital, Chiang Mai, Thailand. The cost of medication was recorded. AR and asthma exacerbations and URTI events were also collected. Results: From between-group comparisons, the cost of medication (THB) in the SCIT group at the one-, two-, and three-year follow up was significantly lower (587.4 (348.3–1374.6) vs. 1562.4 (1315.1–1857.3), p < 0.001, 501.2 (302.9–839.0) vs. 1728.3 (1190.0–2236.1), p < 0.001, and 372.4 (284.8–752.4) vs. 1500.3 (1217.9–1748.9), p < 0.001, respectively)), and AR and asthma exacerbations were significantly reduced at the three-year follow-up. From within-group comparisons, the cost of medication (THB) and AR and asthma exacerbations were significantly lower in the SCIT group at the one-, two-, and three-year follow-up. The URTI event was significantly reduced in the SCIT group at the two- and three-year follow-up. Conclusions: SCIT in subjects with AR with or without asthma was associated with a significantly reduced cost of medication, rates of AR and asthma exacerbations, and URTI events in the long term.

Aeroallergen Sensitization and Clinical Characteristics of Subjects with Chronic Rhinitis in Chiang Mai, Thailand: A Twenty-Year Retrospective Study

Background

The prevalence of common aeroallergen sensitization in subjects with AR and clinical comparison between AR and Non-AR (NAR) subjects in Thailand remains limited. The primary objective of this study was to illustrate the prevalence of the common aeroallergen sensitization in AR subjects and the differences in clinical characteristics between AR and NAR subjects.

Methods

Data were retrospectively collected from all subjects with chronic rhinitis who have visited the Chest and Allergy Clinic in three settings in Chiang Mai, Thailand between January 1998 and December 2018. Clinical characteristics and the result of skin prick test (SPT) to common aeroallergen were collected.

Results

A total of 2164 subjects with chronic rhinitis were enrolled, SPT was performed in 1001 (46.3%); 655 (65.4%) and 346 (34.6%) were AR and NAR, respectively. Mite mixed was the most frequent aeroallergen sensitization in subjects with AR both without asthma and with asthma (86.4% and 85.6%) followed by cockroach mixed (54.4% and 58.9%), grass pollen (38.9% and 40.4%), animal dander (15.5% and 19.9%), and mold mixed (5.7% and 11.0%). Polysensitization was higher in younger adults compared to middle aged adult and older adult (72.5%, 67.4%, and 58.7%, respectively, p=0.041). The AR subjects had lower age, earlier age of disease onset, and longer duration of disease (32.6±16.3 vs 40.2±15.4 years, 24 (10–36) vs 34 years (22–45), 3 (1–10) vs 2 years (0–5), respectively, p<0.001). The AR subjects also had more asthma, conjunctivitis, and family history of chronic rhinitis (22.3% vs 15.6%, 25.3% vs 4.3%, and 58.0% vs 43.3%, respectively, p<0.05).

Conclusion

The most common aeroallergen for AR (with and without asthma) was mite mixed followed by cockroach mixed and grass pollen. Polysensitization was significant higher in younger adult than middle aged and older adult. AR was significantly associated with asthma, conjunctivitis and family history of chronic rhinitis compared to NAR.

The short-term associations of particular matters on non-accidental mortality and causes of death in Chiang Mai, Thailand: a time series analysis study between 2016-2018

Open burnings, agricultural and forest fires, are the major sources of particulate matters (PM) in Chiang Mai during dry season. We aim to determine the association of an increased daily PM (PM₁₀, PM_2.5) and daily non-accidental mortality and causes of death in Chiang Mai. The association between PM and daily non-accidental mortality including causes of death were analyzed using a generalized linear model with Poisson distribution. The results showed that PM₁₀ and PM_2.5 were associated with daily non-accidental mortality on different lag days (adjusted RR range from 1.009-1.018 and 1.016 for each 10 µg/m³ increment of PM₁₀ and PM_2.5, respectively). The causes of death associated with PM₁₀, PM_2.5 found on different lag days were chronic obstructive pulmonary disease (COPD), coronary artery disease (CAD), and sepsis. We concluded that PM₁₀ and PM_2.5 are associated with daily non-accidental mortality and causes of death were COPD, CAD, and sepsis.

Reliability of the Thai version of the International Physical Activity Questionnaire Short Form in chronic obstructive pulmonary disease

OBJECTIVE

To determine the reliability of the Thai version of International Physical Activity Questionnaire Short Form (IPAQ-SF) in Chronic Obstructive Pulmonary Disease (COPD) patients.

METHODS

A cross sectional study was carried out in COPD subjects at Chiang Dao hospital, Chiang Mai, Thailand in June and July 2019. COPD subjects were asked to complete the Thai version of the IPAQ-SF. Calculations for each level of activity were carried out separately (vigorous activity, moderate activity, walking, and sitting). This was carried out twice with an interval of four weeks between visits. The test-retest reliability of the IPAQ was assessed using the intraclass correlation (ICC) with a 95% confidence interval (CI). Cohen's kappa coefficient and percentage agreement were used to test the repeatability of the physical activity classification between the two visits.

RESULTS

Sixty COPD subjects (50% male), with a mean age of 71.2 ± 7.7 years were included. The least reliability was established for sitting time (ICC = 0.439; 95%CI; 0.212, 0.621, p-value < 0.001) and the greatest for the total physical activity (ICC = 0.837; 95%CI; 0.741, 0.899, p-value < 0.001). The Kappa statistic was 0.433 with a 95%CI; 0.237, 0.639, p-value < 0.001 and the percentage agreement of the physical activity classification between the two visits was 66.7%.

CONCLUSION

The test-retest reliability was adequate for vigorous activity and total physical activity. Although there are concerns about the agreement for classification of physical activity, the IPAQ-SF may be a useful if not definitive tool for assessing physical activity in COPD.

The roles of impulse oscillometry in detection of poorly controlled asthma in adults with normal spirometry

BACKGROUND

Impulse oscillometry (IOS) has been introduced as a method of assessing asthma control. However, the cutoff IOS values for the detection of asthma control in adults are still unclear.

OBJECTIVE

To assess the diagnostic ability of IOS for distinguishing between poorly controlled and well controlled adult asthmatic subjects with normal spirometry.

METHODS

This cross-sectional study was conducted at the Lung Health Center, Chiang Mai, Thailand, between July 2019 and June 2020. IOS and spirometry were performed in all adult asthmatic subjects but only subjects with normal spirometry were enrolled. Poorly controlled asthma was defined in accordance with the Global Initiative for Asthma (GINA) plus an asthma control test (ACT) score ≤19. A Receiver Operating Characteristic (ROC) curve was plotted to detect poorly controlled asthma using the area under the ROC (AuROC) and 95%CI.

RESULTS

One hundred and forty-two adult asthmatic subjects registering normal spirometry with a mean age of 53.4 ± 15.8 years were enrolled. Eighty-nine (62.7%) subjects were female. IOS parameters including heterogeneity of resistance at 5 Hz and resistance at 20 Hz (R5-R20) and area under reactance (AX) demonstrated excellent detection of poorly controlled asthma with an AuROC of 0.911 and 0.904, respectively. The z-score or absolute value of R5-R20 ≥ 0 and 1 cmH₂O/L/s, respectively, represented the highest AuROC of 0.86, with a sensitivity and a specificity of ≥80.0% for the detection of poorly controlled asthma.

CONCLUSION

IOS is a valuable tool for the detection of poorly controlled asthma in adults with normal spirometry.

Reference equations of the impulse oscillatory in healthy Thai adults

Background

The ethnicity is significantly under-reported and this may limit the applicability of current impulse oscillometry (IOS) equations to heterogeneous patient populations. Establishing predictive equations for the IOS in the Thai adult population is still required. Therefore, this study aimed to establish reference equations for the IOS in the Thai adult population.

Methods

This retrospective cross-sectional study of IOS parameters in healthy adults aged greater than 20 years old with normal spirometry and who had no chronic respiratory diseases. Pre-bronchodilator (BD) IOS was performed in all subjects. Reference equations were calculated separately for men and women using multivariable linear regression analysis.

Results

A total of 127 subjects (87 men and 40 women) with a mean age of 48.7±17.2 (range, 22–92) years were included. The resistance at 5 Hz (R5), resistance at 20 Hz (R20), and area under reactance curve between 5 Hz and resonant frequency (AX) were significantly higher in women compared to men. The reference equations of the IOS parameters were established for men and women. Age, height, and bodyweight were shown to be the influential predictor as they contributed to the most of IOS indices except for the R5–R20 in men equations. Bodyweight was shown to be the influential predictor as it contributed to the most IOS indices except for the X5 in women’s equations.

Conclusions

We provided the reference equations for the IOS indices in Thai adults. IOS indices including R5, R20, and AX were significantly higher in women compared to men.

Real-world observational study of the evaluation of inhaler techniques in asthma patients

BACKGROUND

Inhaler devices are a keystone in the management of asthma during the maintenance phase of treatment.

OBJECTIVE

To evaluate techniques for using inhaler devices in asthma patients.

METHODS

A prospective cross-sectional study was conducted to assess patient compliance with correct techniques for using inhaler devices across three regimens: pressurized metered-dose inhaler (pMDI), Accuhaler®, and Turbuhaler®. The compliance of patients with essential steps for correct device usage in the case of each regimen was recorded. These were recorded when patients presented for a routine visit and one month after receiving face-to-face training. The percentage of compliance between the use of the devices and the risk factors related to incorrect techniques were analyzed by logistic regression analysis. The percentages of incorrect techniques were compared between the two visits using a Chi-squared test.

RESULTS

A total of 108 asthma patients (35.2% male), with a mean age of 57.5 ± 12.3 years were evaluated. Percentages of incorrect use of Accuhaler®, pMDI, and Turbuhaler® were 50%, 48%, and 55.6%, respectively. The most common incorrectness's is breath out gently to residual volume (approximately one-third). Previous treatment by a pulmonologist for less than 2 years was the single factor related to incorrect technique [Adjusted OR = 2.8 (95%CI, 1.2-6.3), p = 0.02]. Formal training resulted in a statistically significant decrease in percentage of incorrect techniques (52.8% vs. 32.1%, p = 0.02).

CONCLUSIONS

Inhalation technique in asthma patients was mostly unsatisfactory, especially in patients who had been treated by a pulmonologist for less than 2 years. Face-to-face training significantly improved good technique in all devices.

Diagnostic Ability of Impulse Oscillometry in Diagnosis of Chronic Obstructive Pulmonary Disease

The diagnosis of chronic obstructive pulmonary disease (COPD) mainly relies on spirometry. Due to the complexity of spirometry, easier-to-do impulse oscillometry (IOS) has been introduced as a complementary approach to conventional pulmonary function testing. Therefore, this study aimed to assess the efficacy of the diagnostic ability of IOS for diagnosing chronic obstructive pulmonary disease (COPD). This cross-sectional study was conducted at the Lung Health Center, Chiang Mai University, Thailand, between June 2019 and January 2020. IOS and spirometry were performed with all subjects suspected of having COPD. A Receiver Operating Characteristic (ROC) curve was plotted, the area under the ROC (AuROC) and 95%CI were compared among COPD and chronic smokers. One hundred and seventeen subjects suspected of having COPD with a mean age of 68.6 ± 8.6 years old were enrolled. Of these 103 (88.0%) were male. Thirty healthy subjects were also enrolled. IOS parameters including resistance at 5 Hz (R5), resonant frequency (Fres), area under reactance (AX), heterogeneity of resistance (R5-R20), and reactance at 5 Hz (X5) demonstrated excellent overall accuracy relative to the diagnosis of COPD with an AuROC ranging from 0.80 - 0.84. The AX ≥ 8.66 cmH₂O/L represented an AuROC = 0.79, with a sensitivity of 79.1% and a specificity of 78.0% for the diagnosis of COPD. IOS is a valuable tool for use in the diagnosis of COPD. It may be used in subjects who cannot carry out the spirometric procedure.

Diagnostic ability of the Timed Up & Go test for balance impairment prediction in chronic obstructive pulmonary disease

Background

Balance assessment is now recommended by clinical practice guidelines, specific tests have yet to be suggested. The Timed Up and Go (TUG) test is a simple measure of balance status and functional mobility. Nowadays, we need more data of an optimum cut off point of TUG time for detecting balance impairment in patients with chronic obstructive pulmonary disease (COPD). Thus the aim of this study was to evaluate the diagnostic ability relative to balance impairment of the TUG in subjects with COPD.

Methods

The cross-sectional study was conducted in stable COPD patient at Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand from November 2015 to October 2017. Balance impairment test was measured using the Berg Balance Scale (BBS), a score of ≤45 indicates balance impairment. The TUG was evaluated using sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR−), Youden’s index, and the area under receiver operating characteristic curve (AUROC) from various points of TUG to identify the optimum cut-off point for detecting balance impairment. Multivariable logistic regressions were performed to identify the optimum cut off point of TUG test time for prediction of balance impairment in COPD.

Results

One hundred and eighteen smoking related COPD subjects 86 (72.9% male) with a mean age of 73.5±8.1 years were included in this study. Univariable analysis showed that the AUROC of TUG test to indicate those who had impaired balance was 0.93 [95% confidence interval (CI): 0.88, 0.98]. A cut off point of TUG test time ≥12 seconds had sensitivity, specificity, LR+, LR−, Youden’s index, and AUROC of 95.8%, 90.4%, 10.01, 0.05, 86.2, and 0.93 for detecting balance impairment, respectively. Multivariable analysis identified the TUG test time ≥12 seconds was the best predictor of balance impairment in COPD patients with adjusted risk ratio (RR) of 25.2 (95% CI: 1.6, 312.0, P=0.021) and, the AUROC was 0.98 (95% CI; 0.96, 1.00).

Conclusions

Our study indicates the TUG test time ≥12 seconds has a high diagnostic ability for balance impairment prediction in COPD. The result supports a potential role for this simple test to be incorporated into routine COPD assessment to stratify patients’ balance.

PM10-related DNA damage, cytokinetic defects, and cell death in COPD patients from Chiang Dao district, Chiang Mai, Thailand

Exposure to PM₁₀ generated by biomass burning may reduce lung function and induce cytogenetic effects, especially in chronic obstructive pulmonary disease patients. This study investigated the frequency of DNA-damaged cells, cells with cytokinetic defect, and different types of cell death using a buccal micronucleus cytome assay. The correlations between each biomarker and lung function were investigated. The changes in these biomarkers associated with high pollutant levels (PM₁₀ > 50 μg/m³) and low pollutant levels (PM₁₀ < 50 μg/m³) were evaluated to explore whether PM₁₀ exposure induced genotoxic damages and cytokinetic defects in COPD patients when the daily average PM₁₀ concentration reached above 50 μg/m³. Fifty-eight COPD patients and 26 healthy subjects living in Chiang Dao district, Chiang Mai, Thailand, were recruited in this study. The results revealed that buccal cells with micronuclei (high vs low 1.09 ± 1.95 vs 0.29 ± 0.64 in COPD patients) and binucleated cells (high vs low 11.43 ± 18.68 vs 1.60 ± 1.31 and 7.77 ± 12.76 vs 1.00 ± 1.17 in COPD and healthy subjects, respectively) observed during the high pollutant period were more frequent than in the low pollutant period. Moreover, exposure to PM₁₀ increased the risk of micronucleus induction in COPD patients 295.23-fold.

Acute effects of air pollutants on daily mortality and hospitalizations due to cardiovascular and respiratory diseases

Background

Chiang Dao is one of the districts in Chiang Mai, Thailand facing high level of seasonal air pollution every year, the exposure of community dwellers to outdoor air pollutants 24 hours a day during seasonal smog period because of their open-air housing style, and agricultural occupational hazard. In addition, Chiang Dao hospital is the only available hospital serving the community with open-air wards; therefore we could certainly to identify the association between air pollution and mortality of hospitalized patients. Thus, the aim of this study was to determine the association between daily average seasonal air pollutants and daily mortality of hospitalized patients and community dwellers as well as emergency and hospitalization visits for serious respiratory, cardiovascular, and cerebrovascular diseases.

Methods

This time series study was conducted between 1 March 2016 and 31 March 2017. The association of various air pollutant concentrations including particulate matter diameter less than 10 and 2.5 microns (PM₁₀ and PM_2.5), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), ozone (O₃) and daily mortality of hospitalized patients and community dwellers as well as relationship with frequencies of serious respiratory, cardiovascular, and cerebrovascular diseases were analyzed using a general linear model with Poisson distribution.

Results

Only PM_2.5 was found to be associated with increased daily mortality of hospitalized patients (lag day 6, adjusted RR =1.153, 95% CI: 1.001-1.329), whereas PM₁₀, PM_2.5, NO₂, and O₃ were associated with increased daily non-accidental mortality of community dwellers (lag day 0-7, adjusted RR =1.006-1.040, 95% CI: 1.000-1.074). For acute serious respiratory events; PM₁₀ and PM_2.5 were associated with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), while SO₂, CO, and O₃ were associated with emergency visits for community-acquired pneumonia (CAP). O₃ was associated with emergency visits for heart failure (HF), NO₂ with emergency visits for myocardial infarction (MI), and SO₂ with hospitalized visits for cerebrovascular accident (CVA).

Conclusions

Seasonal air pollutants were found to be associated with higher mortality among hospitalized patients and community dwellers with varying effects on severe acute respiratory, cardiovascular, and cerebrovascular diseases.

Effect of the Application of the Global Lung Initiative 2012 Spirometry Reference Equation on the Diagnosing and Classifying Degree of Airway Obstruction in Thai Adults Aged 40 to 80 Years Old

Background and objective: Changing to a different spirometry reference equation can result in misinterpretation of spirometric findings. Currently, there is limited data about any discordance between the interpretations of airway obstruction (AO) using the Global Lungs Initiative (GLI) 2012 and the currently employed Thai reference equations (Siriraj) in Thai adults. Therefore, this study aimed to determine differences in diagnosis around AO and classification of the severity of AO using the GLI2012 and Siriraj reference equations in Thai adults. Materials and Methods: We analyzed spirometric results from Thai adults aged 40–80 years old (n = 2084), which were collected at the Lung Health Center, Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand between January 2005 and December 2015. The diagnoses concerning the AO were interpreted using the GLI2012 and Siriraj reference equations. The severity of AO in each case was classified into five grades, including mild, moderate, moderately severe, severe, or very severe. McNemar’s test was used to analyze differences in diagnosis of AO and classification of the level of severity. The Kappa statistic was used to determine agreements of diagnosis of AO and classification of severity between the two reference equations. Results: There were significant differences in both diagnosis of AO and their classifying severity level between the two reference equations (p-value < 0.001). However, the levels of agreement between the two reference equations were moderate to very good in different age and sex groups (Kappa values ranged from 0.62 to 0.78 for the diagnosis of AO and 0.54 to 0.89 for the classification of severity). Conclusions: Changing from the Siriraj to the GLI2012 reference equations underestimates the proportion of airway obstruction in Thai adults.

Thai adaptation and reliability of three versions of the Barratt Impulsiveness Scale (BIS 11, BIS-15, and BIS-Brief)

Long, short, and brief versions of the Barratt Impulsiveness scale (BIS-11, BIS-15, and BIS-Brief) were tested in an adult Thai population. The BIS-11T and BIS-15T were translated, back-translated, and administered to a non-clinical population (n = 305) of native Thai speakers who returned 2 weeks later for re-test. BIS-Brief-T psychometrics were calculated post-hoc. Impulsivity scores were normally distributed for the BIS-11T and BIS-15T, but not BIS-Brief-T. Excellent internal consistency was observed, with Cronbach's alpha coefficients above 0.80 for all translated instruments: BIS-11T (α = 0.86), BIS-15T (α = 0.81), BIS-Brief-T (α = 0.81). A total of 260 participants completed both instruments (85%), with test-retest reliability exceeding r = 0.81. All three instruments were highly correlated (r = 0.83-0.89). Confirmatory factor analysis supports a three factor structure (attention, motor, non-planning) for BIS-15T and two factor structure for BIS-11T. BIS scales can support measurement of a range of impulsivity scores in an adult Thai population, though predictive validity of these scales remains unexplored.

Effect of changing reference equations for spirometry interpretation in Thai people

Background

Use of different spirometry reference equations can lead to misinterpretation of spirometry results. Currently, no study has been carried out to determine if there is any discordance between the interpretation of spirometry data using the Global Lungs Initiative (GLI) 2012, the Third National Health and Nutrition Examination Survey (NHANES III), the Knudson, and the Siriraj reference equations in Thai people. Therefore, this study aimed to determine differences and agreements regarding spirometry results using the GLI2012, NHANES III, Knudson, and Siriraj reference equations in a Thai population.

Methods

A retrospective study was carried out using 2,492 spirometry results from Thai people (age ranged 8-80 years old) who were referred by their physicians for spirometry testing at the Lung Health Center, Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand between January 2005 and December 2015. The spirometry results were interpreted using four reference equations. Respiratory function patterns were classified as normal, spirometric restriction, obstruction, or mixed defect. The severity of abnormal patterns were classified as mild, moderate, moderately severe, severe or very severe. A Nominal Analysis of Variance (NANOVA) test was used to analyze differences in diagnosis and classification for the degree of severity. The Kappa statistic was used to determine agreements of spirometry results between four reference equations.

Results

The differentiation in both spirometry diagnosis and the severity classification were significant across the four reference equations (P<0.001). However, the levels of agreement among the four reference equations were moderate to good (Kappa values ranged from 0.56 to 0.77 for the diagnosis and 0.67 to 0.82 for the severity).

Conclusions

The results of this study suggest that the use of the GLI2012, NHANES III, Knudson, and Siriraj reference equations alters the interpretation of spirometry data in this population of Thai adults.

Effects of seasonal smog on asthma and COPD exacerbations requiring emergency visits in Chiang Mai, Thailand

BACKGROUND

Seasonal smog produces particulate matters that are less than 10 microns in diameter (PM₁₀), which are known to have several impacts on the respiratory system.

OBJECTIVE

This study was to determine the association of an increased PM10 level due to seasonal smog in Chiang Mai and emergency visits for asthma and chronic obstructive pulmonary disease (COPD) exacerbations.

METHOD

A retrospective cross-sectional study was conducted between the months of January and March from 2006 until 2009. The association of an increased PM₁₀ level and the daily number of asthma and COPD exacerbations were analyzed using a generalized linear model; a Poisson regression model was fit to the number of daily emergency visits using predictor variables: lags of PM10, day of the week, and time.

RESULTS

There were a total of 917 emergency visits for acute exacerbations of asthma and COPD, with a median of 2 visits per day (range 0-10). The median PM₁₀ level during the same interval was 64.5 microgram per cubic meter (μg/m3) (16-304). For every 10 μg/m3 rise in PM10 concentration, there was a lag time of 6 days for asthma exacerbations [Adjusted relative risk (RR)=1.020; 95% confident interval (CI), 1.001-1.040; (p=0.014)], 7 days for COPD exacerbations [RR=1.030; 95%CI, 1.010-1.050 (p=0.024)] and 7 days for all exacerbations [RR=1.030 95%CI, 1.010-1.040 (p<0.001)].

CONCLUSIONS

This study confirms the effect of increasing PM₁₀ concentrations from seasonal smog on asthma and COPD exacerbations. However, there was an approximately 1 week lag time between the elevated PM₁₀ levels and time to emergency visits due to disease exacerbation.

Quality Assurance of Spirometry for COPD Clinic Accreditation in Thailand

OBJECTIVE

To evaluate quality of spirometry for COPD clinic accreditation.

MATERIAL AND METHOD

A minimum of 25 spirograms from each of 38 hospitals were evaluated using the American Thoracic Society (ATS)/European Respiratory Society (ERS) acceptability criteria. Technicians were separated into two groups based on their respective level in spirometry training, previously trained-certified, and naïve (not formally trained-certified) groups. Unpaired t-test and Chi-square were used to compare differences between the two groups. Statistical significance was set at p<0.05.

RESULTS

Thirty-eight technicians from 38 clinics submitted a total of 1,556 spirograms for accreditation evaluation. Of those, 1,066 (68.5%) spirograms met all ATS/ERS acceptability criteria. Only 47.4% of the clinics received an A grade. All clinics that received an A grade were staffed by trained-certified technicians. Significantly, more spirograms failed to meet the criteria from clinics with naïve technicians than clinics with trained-certified technicians (18.2% vs. 80.8%, p-value <0.001). Criteria where the trained-certified group significantly achieved than naive group were satisfactory exhalation (93.4% vs. 20.9%, p-value <0.001), no early termination (98.5% vs. 58.6%, p-value <0.001), maximal effort throughout (96.2% vs. 89.1%, p-value <0.001), and good start (91.6% vs. 79.9%, p-value <0.001).

CONCLUSION

Spirometry performed by the Thoracic Society of Thailand trained-certified technician was distinguishably higher quality than by a naïve technician. Our results are a reminder of the importance of quality assurance for spirometry in clinical practice.

The Risk Factors and Clinical Course of Asthma with Fixed Airflow Limitation

OBJECTIVE

To identify risk factors and clinical course of asthma with fixed airflow limitation.

MATERIAL AND METHOD

A retrospective case-control study of asthma patients was conducted over a 15-month period. Asthma with fixed airflow limitation patients were defined as chronic asthmatics who had both post-bronchodilator (BD) and on-treatment ratio of forced expiratory in first second (FEV1)/forced vital capacity (FVC) persistently less than 0.7, whereas usual chronic asthma patients had post-BD and/or on-treatment ratio of FEV1/FVC more than 0.7. Serial asthma control tests (ACT), medication used, exacerbations were assessed. The risk factors were analyzed using logistic regression. Clinical characteristics between groups were compared using Student’s t-test and Fisher’s exact test.

RESULTS

One hundred twenty from 142 eligible subjects were enrolled. They had asthma with fixed airflow limitation (n = 40) and usual chronic asthma (n = 80). Potential risk factors of asthma with fixed airflow limitation included early disease onset (age <15 years) [(adjusted odd ratio (OR) = 3.9, 95% confidence interval (CI) 1.9-8.3)] with longer disease duration (adjusted OR = 8.4, 95% CI 4.6-15.4 for >30 years). Asthma with fixed airflow limitation patients had lower ACT scores (p<0.001), lower level of asthma control (p<0.001), required more asthma medications (p = 0.002), and higher rates of hospitalization (p = 0.001) than usual chronic asthma.

CONCLUSION

The potential risk factors of asthma with fixed airflow limitation were earlier disease onset and longer disease duration. They had poorer asthma control, more medications needed, and higher rates of exacerbation than usual chronic asthma.

The Relationship between Body Composition and Clinical Parameters in Chronic Obstructive Pulmonary Disease

OBJECTIVE

Identify a correlation between body mass index (BMI) and fat-free mass index (FFMI) to clinical parameters in chronic obstructive pulmonary disease.

MATERIAL AND METHOD

The cross-sectional study was conducted at a single visit involving stable chronic obstructive pulmonary disease (COPD) patients at the outpatient chest clinic of the Chiang Mai University Hospital, Thailand. Eligible patients were evaluated for BMI, FFMI, lung function, modified medical research council (mMRC) dyspnea score, COPD assessment test (CAT) score, and number of acute exacerbation (AE) in the past year. The correlations of FFMI and BMI with other parameters were determined using Pearson correlation coefficient analysis. Body composition was categorized into four groups, normal, semi-starvation, muscle atrophy/sarcopenia, and cachexia based on BMI and FFMI. Statistical significance was accepted at p-value < 0.05.

RESULTS

One hundred twenty one stable COPD patients met study inclusion criteria. The FFMI showed a strong correlation with BMI (r = 0.792, p < 0.001). The FFMI, but not BMI, was significantly correlated with mMRC, precentage ofp redicted forced expiratory volume in first second (FEV₁), and CAT score (r = -0.315, 0.214, and -0.278, respectively). Body composition was categorized into four groups: normal body composition (n = 62, 51.2%), semi-starvation (n = 4, 3.3%), sarcopenia/ muscular atrophy (n = 12, 9.9%), and cachexia (n = 43, 35.5%).

CONCLUSION

FFMI, but not BMI, was significantly correlated with dyspnea severity, lung function, and quality of life. Body composition category assignment is a useful clinical tool.

Major affective disorders in chronic obstructive pulmonary disease compared with other chronic respiratory diseases

Background

Chronic obstructive pulmonary disease (COPD) and other chronic respiratory diseases (CRDs) have significant impacts on quality of life including psychomotor domain.

Purpose

To evaluate three major affective disorders in subjects with COPD compared with other CRDs and nonill population.

Materials and methods

The Thai version of Mini International Neuropsychiatric Interview (MINI) was used as a diagnostic instrument for three major affective disorders (generalized anxiety disorder, major depressive disorder, and panic disorder) by face-to-face interview in assessing patients with CRDs [COPD, asthma, rhinasthma, all asthma (asthma and rhinasthma), and chronic rhinitis], and nonill subjects. Logistic regression analyses were used to determine the relation between major affective disorders and CRDs adjusting for age, sex, and disease severity.

Results

Major affective disorders were more prevalent in CRDs than nonill groups (adjusted OR =2.6 [95% CI, 1.8−3.9], P<0.001). COPD patients had significantly more generalized anxiety and panic disorder (adjusted OR =4.0 [95% CI, 1.4−11.9], P=0.011, and 4.4 [95% CI, 1.1−18.1], P=0.038, respectively) but not major depressive disorder (adjusted OR =2.7 [95% CI, 0.8−9.0, P=0.105]) than nonill group. Comparing with all asthma, COPD patients had lower occurrence of major depressive and panic disorders (adjusted OR =0.1 [95% CI, 0.0−0.4], P=0.002, and 0.1 [95% CI, 0.0−0.9], P=0.043, respectively). There was no difference in major mood disorders in COPD, rhinasthma, and chronic rhinitis patients. Major affective disorders were not increased by disease severity in COPD.

Conclusion

Major affective disorders were significantly higher in CRDs than nonill population. Generalized anxiety and panic disorders were significantly high in COPD patients. Moreover, major depressive and panic disorders in COPD were significantly lower than all asthma. The prevalence of major affective disorders may not be related to severity of COPD.

Evaluating inhaler use technique in COPD patients

Background

Poor inhalation techniques are associated with decreased medication delivery and poor disease control in chronic obstructive pulmonary disease (COPD). The purpose of this study was to evaluate techniques for using inhaler devices in COPD patients.

Methods

A prospective cross-sectional study was conducted to assess patient compliance with correct techniques for using inhaler devices across four regimens, ie, the pressurized metered-dose inhaler (pMDI), the pMDI with a spacer, the Accuhaler^®, and the Handihaler^®. The percentage of compliance with essential steps of correct device usage for each regimen was recorded without prior notification when COPD patients presented for a routine visit, and 1 month after receiving face-to-face training. We compared the percentage of compliance between the devices and risk factors related to incorrect techniques using logistic regression analysis. Percentage of patient compliance with correct techniques was compared between the two visits using the chi-square test. Statistical significance was set at P<0.05.

Results

A total of 103 COPD patients (mean age 71.2±9.2 years, males 64.1%, low education level 82.5%, and percent predicted forced expiratory volume in 1 second 51.9±22.5) were evaluated. Seventy-seven patients (74.8%) performed at least one step incorrectly. Patients using the Handihaler had the lowest compliance failure (42.5%), and the odds ratio for failure with the other devices compared with the Handihaler were 4.6 (95% confidence interval [CI] 1.8–11.8) for the pMDI, 3.1 (95% CI 1.2–8.2) for the pMDI with a spacer, and 2.4 (95% CI 1.1–5.2) for the Accuhaler. Low education level was the single most important factor related to incorrect technique (adjusted odds ratio 4.1, 95% CI 1.2–13.4, P=0.022). Formal training resulted in a statistically significant decrease in percentage of incorrect techniques for all devices and for the pMDI (59.4% vs 48.6%, P<0.001; 72.4% vs 48.3%, P=0.039, respectively).

Conclusion

Inhalation technique in COPD patients without face-to-face training was mostly unsatisfactory, especially in patients with low education levels. The Handihaler was the inhaler device associated with the lowest technique failure. Face-to-face inhalation technique training significantly increased technique compliance for the pMDI.

Peak expiratory flow rate as a surrogate for forced expiratory volume in 1 second in COPD severity classification in Thailand

BACKGROUND

There are limited studies directly comparing correlation and agreement between peak expiratory flow rate (PEFR) and forced expiratory volume in 1 second (FEV1) for severity classification of COPD. However, clarifying the role of PEFR as a surrogate of COPD severity classification instead of FEV1 is essential in situations and areas where spirometry is not routinely available.

PURPOSE

To evaluate the agreement between FEV1 and PEFR using Global initiative for chronic Obstructive Lung Disease (GOLD) severity classification criteria.

MATERIALS AND METHODS

This cross-sectional study included stable COPD patients. Both absolute values and % predicted FEV1 and % predicted PEFR were obtained from the same patients at a single visit. The severity of COPD was classified according to GOLD criteria. Pearson's correlation coefficient was used to examine the relationship between FEV1 and PEFR. The agreement of % predicted FEV1 and % predicted PEFR in assigning severity categories was calculated using Kappa statistic, and identification of the limits of agreement was by Bland-Altman analysis. Statistical significance was set at P-value <0.05.

RESULTS

Three hundred stable COPD patients were enrolled; 195 (65.0%) male, mean age 70.4±9.4 years, and mean % predicted FEV1 51.4±20.1. Both correlations between the % predicted FEV1 and PEFR as well as the absolute values were strongly significant (r=0.76, P<0.001 and r=0.87, P<0.001, respectively). However, severity categories of airflow limitation based on % predicted FEV1 or PEFR intervals were concordant in only 179 patients (59.7%). The Kappa statistic for agreement was 0.41 (95% confidence interval, 0.34-0.48), suggesting unsatisfied agreement. The calculated limits of agreement were wide (+27.1% to -28.9%).

CONCLUSION

Although the correlation between FEV1 and PEFR measurements were strongly significant, the agreement between the two tests was unsatisfied and may influence inappropriate clinical decision making in diagnosis, severity classification, and management of COPD.

Impact of direct substitution of arm span length for current standing height in elderly COPD

Background

Arm span length is related to standing height and has been studied as a substitute for current standing height for predicting lung function parameters. However, it has never been studied in elderly COPD patients.

Purpose

To evaluate the accuracy of substituting arm span length for current standing height in the evaluation of pulmonary function parameters and severity classification in elderly Thai COPD patients.

Materials and methods: Current standing height and arm span length were measured in COPD patients aged >60 years. Postbronchodilator spirometric parameters, forced vital capacity (FVC), forced expiratory volume in first second (FEV₁), and ratio of FEV₁/FVC (FEV₁%), were used to classify disease severity according to global initiative for chronic obstructive lung disease criteria. Predicted values for each parameter were also calculated separately utilizing current standing height or arm span length measurements. Student’s t-tests and chi-squared tests were used to compare differences between the groups. Statistical significance was set at P<0.05.

Results

A total of 106 COPD patients with a mean age of 72.1±7.8 years, mean body mass index of 20.6±3.8 kg/m², and mean standing height of 156.4±8.3 cm were enrolled. The mean arm span length exceeded mean standing height by 7.7±4.6 cm (164.0±9.0 vs 156.4±8.3 cm, P<0.001), at a ratio of 1.05±0.03. Percentages of both predicted FVC and FEV₁ values based on arm span length were significantly lower than those using current standing height (76.6±25.4 vs 61.6±16.8, P<0.001 and 50.8±25.4 vs 41.1±15.3, P<0.001). Disease severity increased in 39.6% (42/106) of subjects using arm span length over current standing height for predicted lung function.

Conclusion

Direct substitution of arm span length for current standing height in elderly Thai COPD patients should not be recommended in cases where arm span length exceeds standing height by more than 4 cm.

A comparative study of COPD burden between urban vs rural communities in northern Thailand

Background

COPD prevalence and consequent burden are expected to rapidly increase worldwide. Until now, there has been no community-based study of COPD in Thailand.

Purpose

We aimed to compare the prevalence, clinical characteristics, disease severity, previous diagnosis, and management of COPD between urban and rural communities.

Materials and methods

A population-based cross-sectional study was designed to compare COPD prevalence and burden in rural and urban communities in Chiang Mai Province, Thailand. The COPD subjects were diagnosed and severity categories assigned using Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. The prevalence between the groups was compared using risk regression analysis. Unpaired t-test and chi-square were used to compare differences between the groups.

Results

There were 574 and 293 enrolled subjects with acceptable spirometry, in rural and urban communities respectively. The prevalence of COPD in general and COPD in females was higher in the rural group (6.8% vs 3.7% and 4.4% vs 0.9%, respectively) across all independent variables. However, after adjustment for age, sex, and smoking status, no significant differences were demonstrated. Although the pulmonary function and disease severity between the two groups were not significantly different, the tendency was more pronounced in the rural group (COPD stage III–IV: 65.0% vs 33.3%). Most of the COPD patients in both groups were underdiagnosed (80.0% vs 77.2%) and undertreated (85.0% vs 81.9%). None of the patients in the study had participated in exercise training programs.

Conclusion

The prevalence of COPD in general and particularly COPD in females tended to be higher, with more severe disease in the rural community. However, both groups were similarly underdiagnosed and undertreated.

Efficacy of a simple and inexpensive exercise training program for advanced chronic obstructive pulmonary disease patients in community hospitals

BACKGROUND

Exercise training is an important part of pulmonary rehabilitation; however it may not be appropriate for large-scale practice in community hospitals due to the complexity of the program and expensive training equipment, including cycle ergometry and treadmills. This study therefore aims to evaluate the efficacy of a more simplified exercise training program with inexpensive training equipment.

METHODS

A multicentre study of a mild to moderate intensity exercise training program was conducted based on incremental strength and endurance with two 35-40-minute sessions per week for 8 weeks. The program was performed by 30 outpatients from five community hospitals. Patients were monitored regularly for various parameters including strength of trained muscles, level of dyspnea, 6-minute walk distance, and quality of life (QoL) at baseline at 1, 2, 3, 6, 9 and 12 months. Unpaired t-tests were applied to determine the progress of trained muscle strength and minimal clinically important differences (MCIDs) were used to assess clinical outcomes.

RESULTS

Thirty patients (13 males, 17 females) were enrolled with a mean age of 69.1±8.9 years, body mass index 20.5±4.4 kg/m(2), and mean % of predicted forced expiratory volume in the first second (FEV1) 45.1±10.8. According to GOLD classification, eight (26.7%) cases were in stage II, 20 (66.7%) cases in stage III, and two (6.6%) cases in stage IV. Limb and chest wall muscle strength, dyspnea level, exercise capacity and QoL showed statistically significant improvements throughout the 12-month follow-up (P<0.01). There were clinically significant improvements in QoL throughout the 12-month follow-up, exercise capacity from months 2 to 12, and dyspnea levels at months 2, 3 and 9.

CONCLUSIONS

The implementation of a simplified and inexpensive exercise training program was shown to be effective for advanced chronic obstructive pulmonary disease patients in community hospitals.

Dialectal influence on chronic pulmonary disease assessment test: the reliability and validity study

Background

Chronic obstructive pulmonary disease (COPD) patients living in many countries are familiar with local dialects rather than the official language. We, therefore, compare the reliability and validity of the COPD Assessment Test (CAT) in Thai and northern Thai dialect versions, in stable COPD patients living in the northern part of Thailand.

Methods

A total of 160 COPD patients were randomly selected for the evaluation of each dialect version of CAT (n=80). The internal consistency of all eight items and test–retest reliability were investigated by using Cronbach’s alpha coefficient and intraclass correlation coefficient (ICCC), respectively. The validity was evaluated by the degree of correlation with St George’s Respiratory Questionnaire (SGRQ) using Pearson’s correlation. The correlations of CAT with clinical parameters such as forced expiratory volume in the first second (FEV₁), modified Medical Research Council scale (mMRC) dyspnea score, and 6-minute walk distance (6-MWD) were also evaluated.

Results

The two versions of CAT showed high internal consistency reliability (Cronbach’s alpha coefficient of 0.82 and 0.76) as well as a high test–retest reliability (ICCC of 0.82 and 0.84) for Thai and northern Thai dialect versions, respectively. The test results revealed that the northern Thai dialect version had good correlation with SGRQ whereas the Thai version correlated only moderately.

Conclusion

The two Thai versions of CAT were proven to be good clinical tools with high reliability and acceptable validity for assessing the quality of life of Thai COPD patients. However, the northern Thai dialect version is more suitable for evaluating COPD patients living in the northern part of Thailand.

Misidentification of airflow obstruction: prevalence and clinical significance in an epidemiological study

Background

The fixed threshold criterion for the ratio of forced expiratory volume in the first second to forced vital capacity (FEV₁/FVC) <0.7 is widely applied for diagnosis of airflow obstruction (AO). However, this fixed threshold criterion may misidentify AO, because thresholds below the fifth percentile of normal FEV₁/FVC (lower limit of normal; LLN) vary with age. This study aims to identify the prevalence of AO misidentification and its clinical significance.

Materials and methods

A cross-sectional population-based study was conducted to identify the prevalence of chronic respiratory diseases in adults older than 40 years of age who live in municipal areas of Chiang Mai province, Thailand. All randomly selected subjects underwent face-to-face interviews and examinations by pulmonologists, and received chest radiographs and post-bronchodilator spirometry. AO misidentification was classified into under- or overestimated AO subgroups. Underestimated AO was defined as ratio of FEV₁/FVC greater than the fixed threshold, but below the LLN criteria. Overestimated AO was defined as the ratio of FEV₁/FVC below the fixed threshold but greater than the LLN criteria. The clinical significance of each misidentified subject was then explored.

Results

There were 554 subjects with a mean age of 52.9±10.1 years and a percent predicted FEV₁ of 85.5%±15.4%. The prevalence of AO misidentification was 5.6% (31/554), and all subjects belonged to the underestimated subgroup. Clinical significance of underestimated subjects included clinical AO disease of 22.6% (7/31) (three subjects with chronic obstructive pulmonary disease [COPD] and four subjects with asthma); chronic respiratory symptoms of 54.8% (17/31) (mostly associated with chronic rhinitis, 70.6% [12/17]); and only 12.9% (4/31) were identified as non-ill subjects.

Conclusion

The prevalence of AO misidentification in this population was significant, and all were underestimated subjects. Most underestimated subjects had clinical significance as related to obstructive airway diseases and chronic respiratory symptoms, mostly associated with rhinitis.

Detection of acute deterioration in health status visit among COPD patients by monitoring COPD assessment test score

Background

The Chronic Obstructive Pulmonary Disease Assessment Test (CAT) could play a role in detecting acute deterioration in health status during monitoring visits in routine clinical practice.

Objective

To evaluate the discriminative property of a change in CAT score from a stable baseline visit for detecting acute deterioration in health status visits of chronic obstructive pulmonary disease (COPD) patients.

Methods

The CAT questionnaire was administered to stable COPD patients routinely attending the chest clinic of Chiang Mai University Hospital who were monitored using the CAT score every 1–3 months for 15 months. Acute deterioration in health status was defined as worsening or exacerbation. CAT scores at baseline, and subsequent visits with acute deterioration in health status were analyzed using the t-test. The receiver operating characteristic curve was performed to evaluate the discriminative property of change in CAT score for detecting acute deterioration during a health status visit.

Results

A total of 354 follow-up visits were made by 140 patients, aged 71.1±8.4 years, with a forced expiratory volume in 1 second of 47.49%±18.2% predicted, who were monitored for 15 months. The mean CAT score change between stable baseline visits, by patients’ and physicians’ global assessments, were 0.05 (95% confidence interval [CI], −0.37–0.46) and 0.18 (95% CI, −0.23–0.60), respectively. At worsening visits, as assessed by patients, there was significant increase in CAT score (6.07; 95% CI, 4.95–7.19). There were also significant increases in CAT scores at visits with mild and moderate exacerbation (5.51 [95% CI, 4.39–6.63] and 8.84 [95% CI, 6.29–11.39], respectively), as assessed by physicians. The area under the receiver operating characteristic curve of CAT score change for the detection of acute deterioration in health status was 0.89 (95% CI, 0.84–0.94), and the optimum cut-off point score was at 4, with a sensitivity, specificity, and accuracy of 76.8%, 83.6%, and 82.4%, respectively.

Conclusions

Change in CAT score during monitoring visits is useful for detecting acute deterioration in health status, and a change of 4 units could make a moderate prediction of acute deterioration in health status.

Long-term efficacy of intensive cycle ergometer exercise training program for advanced COPD patients

Background

Exercise training has been incorporated into the international guidelines for the treatment of chronic obstructive pulmonary disease (COPD). However, the long-term efficacy of the training program for patients with advanced COPD has never been evaluated in Thailand.

Purpose

To determine the long-term efficacy of intensive cycle ergometer exercise program on various clinical parameters of patients with advanced COPD.

Materials and methods

The patients with advanced COPD were separated into two groups: the intensive ergometer exercise program group and the control group. The clinical parameters of all the patients were assessed at baseline, every month for the first 3 months, and then every 3 months until they had completed the 24-month follow-up. Mann–Whitney U test was used to compare baseline mean differences between the groups. Repeated measure analysis was applied to determine the progress in all parameters during the entire follow-up period. Mean incase imputation method was applied to estimate the parameters of dropout cases.

Results

A total of 41 patients were enrolled: 27 in the intensive ergometer exercise program group and 14 in the control group. The intensive cycle ergometer exercise program group showed statistically significant improvements in muscle strength (from month 1 till the end of the study, month 24), endurance time (from month 1 till the end of measurement, month 12) and clinically significant improvements in 6-minute walk distance (from month 2 until month 9), dyspnea severity by transitional dyspnea index (from month 1 till the end of the study, month 24), and quality of life (from month 1 till the end of the study, month 24). There was no significant difference in survival rates between the groups.

Conclusion

The intensive ergometer exercise training program revealed meaningful long-term improvements in various clinical parameters for up to 2 years. These promising results should encourage health care professionals to promote exercise training for patients with advanced COPD who have limited daily activities despite optimal medication control.