Description of Study Participants
While a total of 107 patients were recruited into this study, this interim analysis reports the data analysis of long COVID-19 patients who had completed their baseline PAC-19QoL survey, N=74. For this interim report, the analysis represents the latest updates on 1st Dec 2021. After the exclusion of participants who did not meet the requirements of long COVID-19 symptoms, the descriptive analysis of their PAC-19QoL analysis was calculated (Table 1, Tables S1 – S3.2; Figures S1 - S5).
The health and demographic modules of the participants is presented in Table 1, N = 74. For information on the distribution of the participants by country and by age in quartiles, refer to Tables S1 – S3.2. Body Mass Index (BMI) was achieved by applying the formula: weight (kg) / height(m2) (Figure S2). Median age at recruitment was 45.2 ± 10.3 (F) and 43.8 ± 10.8(M) ( Figure S1.1 & S1.2).
Table 1
Demographic characteristics of participants experiencing COVID-19 symptoms for at least 28 days.
|
All Countries
(N=74)
|
UK-only
(N=59)
|
Females (%)
|
87.8
|
88.1
|
Recruited age (median ±sd)
|
45.2 ± 10.4
|
47.5±9.9
|
Truncation time in days (median ±sd)
|
1 ± 24.3
|
1±33.4
|
Exposure time since diagnosis, days§
(median ± sd)
|
197.0± 113.7
|
169.0±117.4
|
Body Mass Index
|
25.4 ± 9.4
|
25.5±8.9
|
Ethnicity (%)
|
White
|
90.5
|
94.9
|
Mixed
|
1.4
|
1.7
|
Asian
|
2.7
|
1.7
|
Black
|
-
|
-
|
Other
|
5.4
|
1.7
|
Smoking Status (%)
|
Never
|
68.9
|
67.8
|
Former
|
28.4
|
32.2
|
Current
|
2.7
|
1.7
|
Health Status (%)
|
Recovered from COVID-19
|
23.0
|
20.7
|
Hospitalization
|
16.2
|
15.5
|
ICUº
|
41.7
|
44.4
|
Received major surgeries
|
21.6
|
20.7
|
Morbidity (N)
|
Cancer
|
1
|
0
|
Cystic fibrosis
|
1
|
1
|
Stroke
|
0
|
0
|
High cholesterol
|
6
|
4
|
High blood pressure
|
9
|
5
|
Respiratory (COPD, Asthma)
|
24
|
19
|
Diabetes Type I & II
|
3
|
3
|
Other medical conditions
|
33
|
25
|
Well-being (%)
|
Post-COVID-19 mobility
|
75.7
|
78.0
|
Help with grocery shoppingnot required
|
74.3
|
72.9
|
Difficulty sleeping
|
71.6
|
67.8
|
COPD – chronic obstructive pulmonary disease
Participants resided in the United Kingdom (UK), United States, Columbia, Canada, Ireland, Morocco and Belgium (Table 1). Standard deviation was abbreviated as sd. ICUº percentage and was derived from patients who were hospitalized. § Exposure time was conditional for participants with < 28 days exposure, N = 2. The summation of numbers in each category may exceed or be below 1.0 or 100% due to rounding (Table 1).
The COVID-19 diagnosis of 87% of participants was confirmed through testing or clinical diagnosis. The remaining proportion was self-diagnosed without access to professional medical advice. Among participants, 58.7% declared that they had suffered from COVID-19 in the past, and 39.2 % were under full-time employment.
Table 2
Correlation between PAC-19QoL scores at baseline and exposure to long COVID-19 by age group.
Group
|
n
|
Mean
|
Median
|
IQR
|
Correlation coefficient
|
p-value
|
< 30 years
|
11
|
145
|
140
|
132.5,151
|
0.279
|
0.118
|
30-55 years
|
46
|
137.76
|
131.5
|
125.25,142
|
0.052
|
> 55 years
|
17
|
127.76
|
131
|
117,137
|
0.159
|
Control
|
16
|
78.75
|
80
|
64.25,97.5
|
|
|
Validation group
|
15
|
136.33
|
139
|
124,149
|
<0.001*
|
Interim report set
|
74
|
136.54
|
132.5
|
123.5,141.75
|
<0.001*
|
Control group (n=15), Validation group (n=15) and Interim report set (n=74).
* p-value < 0.05 is considered statistically significant
Participant recruitment and retention
Findings from this report suggest that the recruitment rate was low, and attrition remained high with a large proportion dropping out after the first survey (Figure 1). A similar trend was observed after the second survey, in addition to deceleration on the attrition rate.
Statistical Analysis
Six participants completed twelve months in the study, and the twelve accompanying surveys. While this represents only 20% of the sampled population, the probability of participant retention was calculated, using the above data points as a reference (Figure 2). A retention rate of 100% was observed after completion of the send survey.
Model selection and truncation time
During the model selection, truncation time was introduced as a continuous variable and in categorical format: 0 days, 1-14 days; beyond 14 days (Table S4.1). Truncation time refers to the duration to complete the survey upon recruitment. In the finalized model, truncation time was categorized as within and beyond 14 days.