In a recent study published in the Respiratory Research journal, researchers in Hong Kong assessed the deterioration of asthma control in patients recovering from mild to moderate coronavirus disease 2019 (COVID-19).
Asthma is among the most prevalent respiratory disorders worldwide, with viral respiratory infection among the most common asthma triggers. An asthma control test (ACT) is often used to evaluate asthma control since it is a validated, self-administered questionnaire designed for disease monitoring. A 2022 study revealed significantly more patients with poorer asthma control after recovering from COVID-19. Yet, such studies did not categorize the severity of asthma exacerbation nor evaluate ACT changes before and after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.
Study: Worsening of asthma control after recovery from mild to moderate COVID-19 in patients from Hong Kong. Image Credit: WindNight / Shutterstock
About the study
In the present study, researchers examined the relationship between mild-to-moderate SARS-CoV-2 infection and asthma control after recovery from infection.
Almost 950 individuals with asthma are frequently followed up in the Queen Mary Hospital's asthma clinic. Across the enrollment period between 24 May 2022 and 1 November 2022, possibly suitable subjects were selected by the team from this clinic. Asthmatic adults aged 18 years or above were eligible participants. The patients having scheduled asthma clinic follow-ups were recruited. Those diagnosed with mild to moderate SARS-CoV-2 infection 30 to 270 days prior to the study assessment were categorized into the COVID-19 cohort. At the same time, an equal proportion of controls were COVID-19-negative and were classified into the non-COVID-19 cohort.
All patients involved in the study were from the asthma clinic, and all of the patients who attended had recovered from their acute infection and were legally permitted to go to the hospital. Positive rapid antigen tests (RATs) and reverse transcription-polymerase chain reaction (RT-PCR) assays validated COVID-19 diagnosis. In addition, the electronic patient record (ePR) was employed to access patients' records, which included details of all outpatient clinic visits and hospitalizations.
The primary outcome involved the deterioration of asthma control, which is described as a decrease in ACT score of at least three points between 'the immediately preceding visit' and the enrollment visit. The secondary outcomes included the extent of alteration in the ACT scores noted during the enrollment visit, the number of patients with an ACT score of 15 or below at the enrollment visit, and the requirement to escalate asthma maintenance treatment.
During the enrollment period, a total of 221 asthmatic adult patients were enrolled, among which 111 were classified as belonging to the COVID-19 cohort. Five individuals with COVID-19 infection were hospitalized, although none experienced severe COVID-19. The mean age of the entire cohort was 58.0±16.0 years. 80% of the patients also suffered from rhinosinusitis, and 38.9% had atopic dermatitis. The mean forced expiratory volume in one second (FEV1) at baseline was 2.08±0.80 L, and the FEV1/forced vital capacity (FVC) ratio at baseline was 67.0±14.7%. The average ACT score was 20.0±4.0 on the previous visit and 19.0±4.9 on the enrollment visit. Furthermore, 24% of patients displayed worsening of asthma in the 12 months preceding their enrollment visit.
At enrollment visits, 25.3% of patients reported ACT reduction of three or more points, with a more significant proportion noted in COVID-19 patients than in non-COVID-19 patients. The odds ratio (OR) was estimated to be 4.174 after controlling for relevant variables, including gender, age, smoking status, COVID-19 vaccination status, ACT score estimated at 12 months prior, and baseline FEV1.
At the enrollment visit, 14.0% of the participants had uncontrolled asthma, with a larger proportion among COVID-19 patients than among non-COVID-19 patients. Approximately 10% of patients required an increase of a minimum of one Global Initiative for Asthma (GINA) step in their asthma maintenance medication, with a larger proportion of COVID-19 patients requiring an increase compared to the non-infected patients. At the visit conducted 12 months prior, the average ACT was comparable between the non-COVID-19 and COVID-19 groups; however, it was considerably lower in the COVID-19 cohort at follow-up. Additionally, the COVID-19 group experienced a more significant mean decrease in ACT.
The study findings indicated that asthma management worsened following recovery from mild to moderate SARS-CoV-2 infection. The deterioration was consistently reflected in multiple areas, including a decrease in ACT, an increase in asthma maintenance treatment, and an increase in the proportion of uncontrolled asthma cases at follow-up. Also, mild-to-moderate COVID-19 was related to worsened asthma symptoms, a lower ACT score, a higher requirement for the escalation of asthma maintenance, and more uncontrolled asthma post-recovery among asthma patients.