Anxiety in adults with asthma during the coronavirus disease 2019 pandemic: a Canadian perspective

The COVID-19 Associated Anxiety in Allergic Rhinitis and Asthma patients Experiencing Symptoms (CAAARES) survey, conducted online through the ‘Qualtrics XM’ platform, was used for data collection. The CAAARES survey was distributed to participants sourced from a Kingston Allergy Research database in addition to a broader population, mainly focused on Southeastern Ontario, through promotion on several social media outlets. There was no prior knowledge of the prevalence of anxiety in the participant database at the time that the survey was distributed. Responses were collected between April to August 2020, which captured the spring and summer allergy season, when weed pollen, tree pollen, and mold spores are at their annual peak levels overlapping with the initial waves of the COVID-19 pandemic. All participants gave their informed consent by reviewing a Letter of Information and agreeing to participate in the study. The study was reviewed for ethical compliance by the Queen’s University Health Sciences and Affiliated Teaching Hospitals Research Ethics Board.

835 adult participants completed the first iteration of the CAAARES survey. Participants were excluded if they failed to report a location of residence within Canada or if they failed to report a valid response to GAD-7, demographic data (gender, age, employment status, AR status, previous anxiety diagnosis, history of access to mental health services), or asthma diagnosis (Fig. 1).

Anxiety was measured using the Generalized Anxiety Disorder Assessment-7 (GAD-7), a self-reported questionnaire to screen for Generalized Anxiety Disorder (GAD) and assess severity [27]. Participants rated the severity of anxiety symptoms over the previous 2 weeks on a scale of 0 (Not at all sure) to 3 (Nearly everyday). Scores were calculated by summing items, with higher GAD-7 scores indicating greater severity. A score of 10 or higher is suggested as the diagnostic threshold for GAD [27].

Asthma control was measured with the Asthma Control Questionnaire-6 (ACQ-6), a self-reported questionnaire assessing participant’s asthma control in the preceding week [28, 29]. Participants rated six sections (nighttime awakenings, symptoms upon awaking in the morning, impact on activity, shortness of breath, wheezing, and short acting bronchodilator use). Scores were calculated by determining the mean of all items, with greater scores indicating poorer asthma control.

Participant responses with missing input for variables being tested were selectively excluded to maximize sample size and power of statistical tests being conducted. All analyses, including Chi square tests, t tests, regressions, and correlations, used a p value cut-off of p ≤ .05 in determining statistical significance. All regression coefficients reported are standardized. All participant data were deidentified. All analyses were conducted with IBM SPSS Statistics 28.

A cross-sectional analysis was conducted to compare anxiety in a group of participants with asthma with that of a control group, defined as participants with or without AR self-identifying as not having asthma. A total of 741 responses were included, 244 participants with asthma (32.9% of total included responses) and 497 participants without asthma (67.1% of total included responses). The baseline demographic characteristics of the asthma group and the control group are summarized in Table 1. Chi square testing showed that more participants in the asthma group had AR and previous anxiety syndrome diagnosis compared with the control group.

Figure 2 compares the percentage of participants in the asthma and control groups reporting GAD-7 scores indicating minimal anxiety (GAD-7 0–4), mild anxiety [5‐9], moderate anxiety [10‐14], and severe anxiety [15‐21]. Participants meeting the diagnostic criteria for GAD are indicated by the red boxes (GAD-7 score ≥ 10). In the asthma group, 31.6% of respondents met the diagnostic criteria for GAD, compared with 26.2% in the control group. The mean GAD-7 scores in the asthma and control groups were 7.50 (SD = 5.80) and 6.70 (SD = 5.47), respectively. There was no significant difference in mean GAD-7 scores between the two groups when compared with a two-tailed t-test (t(739) = 1.83, p = .067).

To assess the impact of asthma status on GAD-7 scores while controlling for other variables, a hierarchal multiple regression (HMR) was conducted, as summarized in Table 2. Predictor variables (demographic variables and COVID-19-specific parameters) were included in the model if they were determined to have a significant predictive effect on GAD-7 score in bivariate analyses or if they were not balanced between the asthma and control groups at baseline as determined by Chi square testing (Table 1). Predictor variables meeting this inclusion criteria included sex, age, asthma status, AR status, previous anxiety syndrome or symptom diagnosis, current access of mental health services (MHS), past access of MHS, general COVID-19-related worry, and perceived COVID-19 stress of others. Sex was coded as a binary variable and participants who did not identify with the gender binary or who preferred not to disclose their gender identity were not included owing to insufficient sample size (Table 1). The parameter of general COVID-19-related worry was assessed by asking respondents how they felt about the current situation with COVID-19 in general (not worried, somewhat worried, worried, or extremely worried). To assess the parameter of perceived COVID-19 stress of others, respondents were asked to separately rate the level of stress associated with COVID-19 they believed others around them were experiencing (family, relatives they did not live with, and close friends) on a Likert scale from 0 to 10 (10 being the most worried). The mean of these 3 values formed the composite measure of perceived COVID-19 stress of others, which had good internal consistency when tested by Cronbach’s alpha (α = 0.79). After filtering for survey responses with valid responses to the included parameters, the sample size of the HMR model was n = 704.

Table 2 displays the results of this HMR model. The overall regression was statistically significant with R² = 0.39 (F(8,695) = 55.26, p < .001), indicating that the model provided a reasonable fit for predicting GAD-7 scores. After asthma status was added as a predictor variable to Model 1a to construct Model 1b, there was no change in the predictive value of the model ΔR² = 0.00, F(1,694) = 0.023, p = .879). In other words, asthma status did not have a significant predictive effect on GAD-7 score after controlling for the effect of covariates (β = 0.00, p = .879).

A subgroup analysis of cases (n = 231) was conducted to explore factors associated with anxiety within the asthma group, including the asthma burden of disease and COVID-19-specific concerns. The mean ACQ-6 score was 1.02 (SD = 0.94). To assess the relationship between burden of disease and anxiety, the linear correlation between GAD-7 score and the ACQ-6 score was calculated. There was a statistically significant weak positive correlation between GAD-7 score and ACQ-6 score (r(244) = 0.22, p < .001).

To assess the impact of asthma burden of disease on anxiety while controlling for the effect of other variables, a second HMR was conducted within the asthma subgroup as summarized in Table 3. Predictor variables again were included if they were determined to have a significant predictive effect on GAD-7 scores within the asthma subgroup in bivariate analyses. These predictor variables were sex, age, previous anxiety syndrome or symptom diagnosis, current access of MHS, past access of MHS, general COVID-19-related worry, perceived COVID-19 stress of others, being treated differently by others, worry about the asthma-COVID-19 symptom overlap, and worry about increased COVID-19 risk. The parameter of being treated differently by others was assessed by a dichotomous yes or no question asking respondents if their friends or family treated them differently when they showed asthma symptoms. The parameter of worry about the asthma-COVID-19 symptom overlap was assessed by asking participants how worried they were that they would mistake their normal asthma symptoms for symptoms of COVID-19 (not worried, somewhat worried, worried, or extremely worried). Finally, the parameter of worry about increased COVID-19 risk was assessed by asking participants how worried they were that having asthma would increase their risk of developing serious symptoms from COVID-19 (not worried, somewhat worried, worried, or extremely worried). After the exclusion of survey responses without valid responses to the included parameters, the sample size of the subgroup HMR was n = 231.The overall regression was statistically significant with R2 = 0.39 (F(9,221) = 15.41, p < .001), indicating that the model provided a reasonable fit for predicting GAD-7 scores. After ACQ-6 score was added as a predictor variable to Model 2a to construct Model 2b, there was no change in the predictive value of the model ΔR2 = 0.007, F(1,220) = 2.48, p = .117). In other words, ACQ-6 score did not have a significant predictive effect on GAD-7 score after controlling for the effect of covariates within the asthma subgroup (β = 0.09, p = .117).

The perceived COVID-19 stress of others was identified as a significant predictor of anxiety in asthma participants in Model 2b of the subgroup HMR. To further investigate the impact of this COVID-19-specific parameter on the relationship between ACQ-6 score and GAD-7 score, a simple mediation model was tested using Hayes’s PROCESS with 95% confidence intervals (CIs), 10,000 bootstrap samples, and standardized regression coefficients. Age and previous anxiety syndrome or symptom diagnosis were included as covariates in the mediation model because they had significant predictive effects in Model 2b. After the exclusion of survey responses without valid responses to the included parameters, the sample size of the subgroup mediation model was n = 242. With the model including ACQ-6 as the independent variable, GAD-7 score as the dependent variable, and the perceived COVID-19 stress of others as a mediator, it did not show that perceived COVID-19 stress was a significant mediator of the relationship between ACQ-6 and GAD-7 (indirect effect β = 0.014, 95% CI=[-0.020,0.048]). Finally, we sought to understand whether individuals presented ifferentlyin terms of GAD-7 or perceived COVID-19 stress of others depending on their asthma control (Fig. 3). We defined poor asthma control as an ACQ-6 score ≥ 1.5 (n = 67). Perceived COVID-19 stress was not a significant mediator of the relationship between ACQ-6 and GAD-7 (indirect effect β=-0.007, 95% CI=[-0.081,0.085]) with ACQ-6 as the independent variable, GAD-7 score as the dependent variable, and the perceived COVID-19 stress of others as a mediator.