Obstructive Lung Diseases and COVID-19 Severity

Obstructive Lung Diseases and COVID-19 Severity

The questions below are loosely based on the following article: Moschovis et al. Effect modification by age of the association between obstructive lung diseases, smoking, and COVID-19 severity. DOI: 10.1136/bmjresp-2021-001038

Complete the right column of the table below.

Exposure

Number of severe COVID-19 cases in this category

Total number of people in this category

Cumulative incidence of severe COVID-19 (per 100 people)

Under 65 years of age  

Asthma

 25

1500

No asthma

124

20304

 65 or older

Asthma

35

2006

No asthma

1761

47480

2. Do the data presented above argue that age should be considered in identifying individuals at higher risk for severe COVID-19 in this population? Justify your answer by showing and interpreting the following separately for the two age groups: the relative risk (risk ratio) and attributable risk (risk difference per 100 persons) for severe COVID-19 associated with asthma compared to no asthma. Please show your calculations and units. Round using accepted rules (reasonable rounding will be accepted). Assume any difference of less than 10% is not statistically significant.

3. Is there effect measure modification on either the additive or the multiplicative scale? Justify your answer.

4. Which scale—additive or multiplicative– is more useful for your purposes of establishing public health guidelines?

Extra credit: What is the main reason to examine effect measure modification on the other scale (the one you did not choose in question 4)?

5. In this population, is age an effect measure modifier or a confounder of the relationship between asthma (exposure) and severe COVID-19 (outcome), or both an effect measure modifier AND a confounder? Like last week, discuss this question using the three criteria for confounding

https://bmjopenrespres.bmj.com/content/8/1/e001038