Residents
In total, 70 residents agreed to participate (70% response rate). A total of 42 residents (60%) died during the study period (March 1. 2020 – March 1. 2022). These residents were significantly older (87 years versus 81 years), were more often staying in a PG ward (57% versus 29%), had more morbidities (3.5 versus 2.6), more often suffered from multimorbidity (86% versus 43%) and were more frequently diagnosed with dementia (71% versus 40%) (Table 1).
Table 1: Baseline characteristics of the study-population
|
Total
(n=70)
|
Deceased
(n=42)
|
Survivors
(n=28)
|
P
|
Age (years), mean (SD)
|
84.7 (7.7)
|
87.2 (5.3)
|
80.9 (9.2)
|
<0.001*
|
Sex, n(%)
Male
Female
|
21 (30.0)
49 (70.0)
|
11 (26.2)
31 (73.8)
|
10 (35.7)
18 (64.3)
|
0.394
|
Ward, n(%)
Psychogeriatric
Somatic
|
32 (45.7)
38 (54.3)
|
24 (57.1)
18 (42.9)
|
8 (28.6)
20 (71.4)
|
0.019
|
BMI, mean (SD)
|
25.6 (5.2)
|
25.3 (5.4)
|
26.1 (4.8)
|
0.801*
|
Barthel index, mean (SD)
|
9.0 (5.0)
|
8.9 (4.5)
|
9.2 (5.7)
|
0.507*
|
Number of comorbidities, mean (SD)
|
3.2 (1.2)
|
3.5 (1.1)
|
2.6 (1.2)
|
0.002*
|
Multimorbidity (≧3 comorbidities), n(%)
|
48 (68.6)
|
36 (85.7)
|
12 (42.9)
|
<0.001
|
Medical history, n(%)
|
|
|
|
|
Dementia
|
41 (58.6)
|
30 (71.4)
|
11 (39.3)
|
0.007
|
Cardiac diseases
|
58 (82.9)
|
35 (83.3)
|
23 (82.1)
|
1.00§
|
Cerebrovascular events
|
24 (34.3)
|
11 (36.3)
|
13 (46.4)
|
0.081
|
Epilepsy
|
7 (10.0)
|
5 (11.9)
|
2 (7.1)
|
0.694§
|
Diabetes mellitus
|
16 (22.9)
|
11 (26.2)
|
5 (17.9)
|
0.416
|
Pulmonary disease
|
12 (17.1)
|
8 (19.0)
|
4 (14.3)
|
0.751§
|
Morbus Parkinson
|
9 (12.9)
|
7 (16.7)
|
2 (7.1)
|
0.299§
|
Malignancy
|
15 (21.4)
|
12 (28.6)
|
3 (10.7)
|
0.074
|
Psychiatric disorder
|
13 (18.6)
|
9 (21.4)
|
4 (14.3)
|
0.452
|
Decreased renal function (eGFR<60)
|
20 (28.6)
|
16 (38.1)
|
4 (14.3)
|
0.031
|
Used statistical tests:
. chi square
*. Independent t-test
§. Fisher’s exact test
Bold: p<0.05, statistical significant difference.
COVID-19
During the study period 50 residents were tested for COVID-19 using PCR of which 35 (70%) tested positive. Amongst the 20 residents not tested, nine were clinically highly suspicious for COVID-19 during the first wave. The remaining 11 residents were not tested and remained without symptoms: they were considered to be negative.
Within the first three months of the study (the first COVID-19 wave) 40 residents were tested or clinically suspect to be positive for the virus. Thereafter only four additional infections were confirmed: one in January 2021 and three around December 2021.
Mortality
During the first outbreak, 87.5% (n=21) of all deaths were caused by COVID (table 2). When looking at the total number of deaths caused by COVID during the total study period (n=22), it appeared that 95% occurred during the first outbreak. Within the COVID-positive group 23% (n=10) died due to a cause that was not COVID-related. These 10 deaths all occurred after the first wave and after these residents had recovered from the infection.
Overall mortality was 60% (n=42), whereas the COVID-related mortality was 31.4% (n=22).
Table 2: Causes of death during the course of the study, comparing the first outbreak to the rest of the study period
|
Total
(n=42)
|
During the first outbreak (n=24)
|
After the first outbreak (n=18)
|
COVID related
|
22 (52.4)
|
21 (87.5)
|
1 (5.6)
|
Directly
|
21 (47.6)
|
21 (87.5)
|
0
|
Secundary
|
1 (2.4)
|
0
|
1 (5.6)
|
Not COVID related
|
20 (47.6)
|
3 (12.5)
|
17 (94.4)
|
Cardiac
|
4 (9.5)
|
1 (4.2)
|
3 (16.7)
|
Cerebrovascular event
|
2 (4.8)
|
1 (4.2)
|
1 (5.6)
|
Pulmonary
|
2 (4.8)
|
0
|
2 (11.1)
|
Dementia
|
3 (7.1)
|
0
|
3 (16.7)
|
Infection (excl. pneumonia)
|
2 (4.8)
|
0
|
2 (11.1)
|
Fracture
|
2 (4.8)
|
0
|
2 (11.1)
|
Overall deterioration
|
3 (7.1)
|
1 (4.2)
|
2 (11.1)
|
Malignancy
|
2 (4.8)
|
0
|
2 (11.1)
|
Figure 1 shows the Kaplan-Meier survival curve for the three different COVID-groups: PCR positive, PCR negative or not tested. The differences in survival were found to be significant using log-rank analysis (p = 0.006).
Deaths in the COVID-positive group totaled 32 (72.7%) for the entire study period. This was significantly higher than the negative group (n=5, 33.3%; p=0.006), but not the not-tested group (n=5, 45.5%; p=0.148).
Almost half of COVID-positive residents (n=21, 47.7%) died during the first outbreak. Mortality was lower during this period amongst the COVID-negative (n=1, 6.7%) and the not-tested residents (n=2, 22.2%). Regarding the nine clinically suspect residents: all died within a couple of days after becoming severely ill.
During the period after the first outbreak, a total of 30 residents died: 23 (52.2%) within the COVID-positive group, 4 (28.6%) within the test-negative group and 3 (3.33%) within the not-tested group.
Multiple logistic regression analysis (table 3) revealed that both being COVID-positive (OR 8.2, 95% CI 1.6-41.9; p=0.012) and suffering from multimorbidity (OR 7.3, 95% CI 1.5-34.4; p=0.012) independently increased mortality risk during the first wave.
Table 3: Multiple logistic regression analysis of mortality within the first wave (March 1, 2020 to June 1, 2020)
|
OR
|
95% CI
|
p
|
COVID status (positive versus not-positive*)
|
8.148
|
1.584-41.910
|
0.012
|
Age
|
1.076
|
0.973-1.190
|
0.152
|
Sex (male versus female)
|
1.336
|
0.344-5.186
|
0.676
|
Ward (PG versus somatic)
|
1.767
|
0.399-7.824
|
0.453
|
Barthel at start of study
|
1.003
|
0.875-1.149
|
0.967
|
Multimorbidity (≧3 versus < 3 comorbidities)
|
7.272
|
1.539-34.361
|
0.012
|
* positive PCR or clinically suspect versus COVID negative or not tested (and no clinical symptoms)
OR = Odds Ratio, which was adjusted for the other variables in the model.
95% CI = 95% confidence interval
Bold: p≤0.05, statistical significant difference.
Vaccinations and multi-infections
The surviving residents (n=39) were offered their first vaccination on February 3rd 2021. 34 residents (87.2%) were vaccinated. Five residents remained unvaccinated because they and/or their representatives refused vaccination. The first repeat vaccination took place on December 9th 2021, which was received by 26 (86.7%) of the remaining 30 residents.
During the study period, two residents were infected by COVID-19 twice. They were male, 68 and 92-years old, and got re-infected respectively in December 2021 and February 2022. Both residents suffered from mild symptoms. Due to preferences of the relatives one of these residents had not been vaccinated, the other one had been vaccinated three times by the time of the re-infection.
Level of functioning / Barthel index score
Figure 2 shows the course of the BI-scores during the study period. BI-scores of the COVID-positive group were lower than the scores of the COVID-negative group, although not significantly different at any point in time. Table 4 shows the observed means and estimated mean difference with 95% confidence intervals and p-values.
Table 4: Observed means and estimated differences of the Barthel Index at each time point
Time (months)
|
Observed
|
Estimated
|
COVID positive*
|
COVID negative*
|
N
|
Mean
|
SD
|
N
|
Mean
|
SD
|
Mean difference
|
P
|
95% CI
|
0
|
44
|
8.8
|
4.7
|
26
|
9.4
|
5.5
|
-0.5
|
0.686
|
-3.0 - 2.0
|
6
|
22
|
8.1
|
4.9
|
22
|
8.7
|
5.5
|
-1.5
|
0.266
|
-4.1 – 1.1
|
12
|
17
|
7.4
|
5.5
|
21
|
7.9
|
5.5
|
-1.9
|
0.186
|
-4.7 – 0.9
|
18
|
13
|
7.5
|
5.7
|
20
|
6.4
|
5.5
|
-1.7
|
0.311
|
-4.9 – 1.6
|
24
|
11
|
6.9
|
5.1
|
16
|
5.5
|
5.7
|
-2.2
|
0.243
|
-5.9 – 1.5
|
*. COVID positive = positive PCR or clinically suspect; COVID negative = test negative or not tested (and asymptomatic).