Methods
Validation study
Reliability study
Infectious disease questionnaire
Self-reported infections (IN1–7) and self-reported symptoms (F1–3)
Self-assessed vulnerability to infections (IH1–5)
Other questions
Definitions
Statistical analysis
Validation of self-assessed vulnerability
Reliability study
Results
Total sample
n (%) | Subsample of reliability study
n (%) | |
---|---|---|
Sex
| ||
Female | 162 (49.7) | 47 (53.4) |
Male | 163 (50.0) | 41 (46.6) |
Missing values | 1 (0.3) | – |
Age
| ||
20–29 years | 24 (7.4) | 5 (5.7) |
30–39 years | 30 (9.2) | 9 (10.2) |
40–49 years | 85 (26.1) | 20 (22.7) |
50–59 years | 87 (26.7) | 22 (25.0) |
60–69 years | 99 (30.4) | 32 (36.4) |
Missing values | 1 (0.3) | – |
School educationa
| ||
Low | 51 (15.9) | 18 (20.5) |
Middle | 118 (36.2) | 35 (39.8) |
High | 151 (46.3) | 34 (38.6) |
Missing values | 6 (1.8) | 1 (1.1) |
Net equivalent incomeb
| ||
≤ 1500 € | 82 (25.2) | 25 (28.4) |
1501–3000 € | 153 (46.9) | 43 (48.9) |
> 3000 € | 62 (19.0) | 14 (15.9) |
Missing values/not specified | 29 (8.9) | 6 (6.8) |
Migration statusc
| ||
No migration background | 263 (80.7) | 78 (88.6) |
Migration background | 59 (18.1) | 9 (10.2) |
Missing values/not specified | 4 (1.2) | 1 (1.1) |
Study regions | ||
Hamburg | 161 (49.4) | – |
Hanover | 165 (50.6) | 88 (100) |
Self-assessed vulnerability to infections
Infections | Less prone to infections (n = 53) % | Similarly prone to infections (n = 181) % | More prone to infections (n = 58) % |
---|---|---|---|
Upper respiratory tract infections (IH1) | |||
Far less frequent | 100 | 19.3 | 0 |
Less frequent | 0 | 53.0 | 19.0 |
Approximately equally frequent | 0 | 17.1 | 50.0 |
More often | 0 | 8.8 | 22.4 |
Much more often | 0 | 1.7 | 8.6 |
Lower respiratory tract infections (IH2) | |||
Far less frequent | 100 | 39.8 | 1.7 |
Less frequent | 0 | 45.3 | 25.9 |
Approximately equally frequent | 0 | 12.2 | 58.6 |
More often | 0 | 2.2 | 8.6 |
Much more often | 0 | 0.6 | 5.2 |
Gastrointestinal tract infections (IH3) | |||
Far less frequent | 100 | 32.0 | 6.9 |
Less frequent | 0 | 48.6 | 25.9 |
Approximately equally frequent | 0 | 14.4 | 51.7 |
More often | 0 | 4.4 | 10.3 |
Much more often | 0 | 0.6 | 5.2 |
Bladder or kidney infections (IH4) | |||
Far less frequent | 100 | 52.5 | 3.4 |
Less frequent | 0 | 43.1 | 22.4 |
Approximately equally frequent | 0 | 3.3 | 53.4 |
More often | 0 | 1.1 | 19.0 |
Much more often | 0 | 0 | 1.7 |
Infections of skin and mucosa (IH5) | |||
Far less frequent | 100 | 50.3 | 12.1 |
Less frequent | 0 | 38.1 | 29.3 |
Approximately equally frequent | 0 | 8.8 | 46.6 |
More often | 0 | 2.2 | 8.6 |
Much more often | 0 | 0.6 | 3.4 |
Reliability study
Item | Answer categories on ordinal scale (0– “ 4 times”) | Answer categories on or interpreted as nominal scale (incl. “Don’t know” and missings) | ||||
---|---|---|---|---|---|---|
n
| Linear weighted agreement [%] | Linear weighted Kappa and 95 % - confidence interval |
n
| Non-weighted agreement [%] (Bennet’s S) | Non-weighted k and 95 % - confidence interval | |
Disease-based itemsa
| ||||||
URT infections (IN1) | 72 | 92.7 | 0.77 [0.67–0.86] | 75 | 73.3 (0.69) | 0.65 [0.53–0.77] |
Visit to GP or outpatient department (IN1a) | – | – | – | 74 | 90.5 (0.87) | 0.75 [0.62–0.90] |
Hospitalisation (IN1b) | – | – | – | 74 | 97.3 (0.96) | 0 [n.c.] |
LRT infections (IN2) | 73 | 97.9 | 0.84 [0.67–0.92] | 75 | 89.3 (0.88) | 0.70 [0.49–0.83] |
Visit to GP or outpatient department (IN2a) | – | – | – | 73 | 87.7 (0.84 | 0.50 [0.18–0.75] |
Hospitalisation (IN2b) | – | – | – | 73 | 89.0 (0.85) | 0.16 [-0.01–0.37] |
GIT infections (IN3) | 72 | 93.7 | 0.73 [0.57–0.87] | 75 | 76.0 (0.72) | 0.59 [0.46–0.75] |
Visit to GP or outpatient department (IN3a) | – | – | – | 73 | 91.8 (0.89) | 0.57 [0.22–0.83] |
Hospitalisation (IN3b) | – | – | – | 73 | 94.5 (0.93) | −0.02 [-0.06–0] |
Lip herpes (IN4) | 73 | 98.6 | 0.87 [0.69–0.97] | 75 | 92.0 (0.91) | 0.75 [0.58–0.90] |
Infections of skin or mucosa (IN5) | 73 | 98.3 | 0.65 [0.20–0.94] | 75 | 93.3 (0.92) | 0.42 [0.09–0.65] |
Bladder infection (IN6) | 73 | 99.0 | 0.83 [0.69–0.93] | 75 | 94.7 (0.94) | 0.74 [0.50–0.89] |
Kidney infection (IN7) | 72 | 99.7 | 0.86 [0.85–0.86] | 74 | 95.9 (0.95) | 0.24 [0.16–0.40] |
Symptom-based itemsa
| ||||||
Cough (F1) | 72 | 97.2 | 0.77 [0.52–0.95] | 75 | 89.3 (0.88) | 0.67 [0.47–0.84] |
Fever (F2) | 71 | 98.2 | 0.77 [0.60–0.93] | 75 | 88.0 (0.86) | 0.59 [0.44–0.78] |
Diarrhoea (F3) | 72 | 97.2 | 0.90 [0.81–0.96] | 75 | 86.7 (0.84) | 0.77 [0.65–0.89] |
Self-assessed comparison to peers | ||||||
URT infections (IH1) | 86 | 91.0 | 0.68 [0.57–0.79] | 87 | 65.5 (0.59) | 0.52 [0.39–0.67] |
LRT infections (IH2) | 87 | 94.0 | 0.74 [0.62–0.84] | 87 | 78.2 (0.74) | 0.67 [0.55–0.79] |
GIT infections (IH3) | 87 | 92.5 | 0.70 [0.57–0.80] | 87 | 71.3 (0.66) | 0.58 [0.42–0.71] |
Bladder and kidney infection (IH4) | 85 | 94.7 | 0.77 [0.62–0.86] | 87 | 80.5 (0.77) | 0.69 [0.56–0.81] |
Infections of skin or mucosa (IH5) | 87 | 94.0 | 0.69 [0.52–0.81] | 87 | 80.5 (0.77) | 0.66 [0.49–0.77] |
Other | ||||||
Use of antibioticsa (A1) | 72 | 96.2 | 0.78 [0.66–0.89] | 74 | 83.8 (0.81) | 0.70 [0.55–0.84] |
Influenza vaccination (V1) | – | – | – | 88 | 92.0 (0.89) | 0.84 [0.73–0.93] |