Table 2

Trends over time in risk perception, anxiety and behavioural responses

Survey 1

30 April-4 May

(n = 456)

Survey 2

15-19 June

(n = 478)

P-value

survey

1 vs. 2

Survey 3.1

follow-upτ

11-20 August

(n = 456)

P-value

survey

1 vs. 3.1

Survey 3.2

follow-upπ

11-20 August

(n = 478)

P-value

survey

2 vs. 3.2

Time trend

1-2

2-3


Knowledge

1. The new flu is caused by a new influenza virus (correct)

74%

79%

ns

84%

< 0.001

86%

< 0.001

ns

+

2. A vaccine is available against the new flu (incorrect)§

50%

47%

ns

37%

< 0.001

36%

< 0.001

ns

3. The new flu can be transmitted by human-to-human contact (correct)

97%

98%

ns

98%

ns

99%

ns

ns

ns

4. People died from the new flu (correct)

97%

97%

ns

99%

0.03

99%

ns

ns

ns

5. The new flu can be transmitted through eating pork (incorrect)

91%

90%

ns

95%

0.004

94%

0.01

ns

+

6. Symptoms of the new flu are visible (incorrect)

81%

81%

ns

90%

< 0.001

87%

< 0.001

ns

+

7. A flu pandemic occurs once in 10-50 years (correct)

-

56%

-

50%

-

60%

ns

ns

Summary score (4 or more correctly answered)

88%

92%

0.02

96%

< 0.001

95%

0.05

+

+









Perceived severity (scale 1-5)

1. Severity of the new flu (score 4-5, severe-very severe)

80%

67%

< 0.001

43%

< 0.001

39%

< 0.001

2. Severity of getting the new flu coming year (score 4-5, severe-very severe)

70%

61%

0.002

39%

< 0.001

39%

< 0.001

3. The new flu is very harmful for my health (score 4-5, mostly-totally agree)

-

49%

-

31%

-

27%

< 0.001

Summary score items 1-2 (high) - Chronbach alpha 0.8

64%

53%

< 0.001

29%

< 0.001

29%

< 0.001









Perceived vulnerability (scale 1-5)

1. Perceived susceptibility (score 4-5, quite-very susceptible)

18%

22%

ns

26%

0.02

30%

0.003

ns

+

2. Perceived chance of getting infected next year (score 4-5, likely-very likely)

5%

5%

ns

15%

< 0.001

15%

< 0.001

ns

+

3. Perceived chance of getting infected compared to others

(score 4-5, more-much more)

6%

6%

ns

9%

ns

12%

< 0.001

ns

+

Summary score (high) - Chronbach alpha 0.6

15%

16%

ns

29%

< 0.001

31%

< 0.001

ns

+









Perceived anxiety (scale 1-5)

1. Worried about the new flu (score 4-5, worried-very worried)

36%

19%

< 0.001

16%

< 0.001

14%

0.02

2. Fear for the new flu (score 4-5, scared-very scared)

16%

8%

< 0.001

6%

< 0.001

4%

0.009

3. Thinking about the new flu (score 4-5, often-very often)

27%

9%

< 0.001

12%

< 0.001

15%

0.003

+

Summary score (high) - Chronbach alpha 0.8

61%

40%

< 0.001

39%

< 0.001

36%

ns

ns









Perceived efficacy (scale 1-5; certainly not-certainly)

1. Keep away from crowded places (score 4-5)

55%

47%

0.01

58%

ns

54%

0.01

+

2. Practice better hygiene (score 4-5)

80%

75%

ns

89%

< 0.001

89%

< 0.001

ns

+

3. Avoid regions/persons¥ with new flu (score 4-5)

82%

73%

0.001

74%

0.002

73%

ns

ns

4. Wear face mask (score 4-5)

34%

31%

ns

22%

< 0.001

25%

0.009

ns

5. Seek medical advice with the onset of flu symptoms (score 4-5)

78%

72%

0.03

70%

< 0.001

66%

0.03

6. Take antiviral medication (score 4-5)

37%

46%

0.005

40%

ns

39%

0.01

+

7. Stay home from school or work (score 4-5)

18%

21%

ns

33%

< 0.001

31%

< 0.001

ns

+

8. Get a new vaccine against the new flu (score 4-5)

-

54%

-

49%

-

53%

ns

ns

Summary score items 1-7 (high) - Chronbach alpha 0.7

50%

38%

< 0.001

50%

ns

50%

< 0.001

+









Perceived self-efficacy* (scale 1-5; certainly not-certainly)

1. Keep away from crowded places (score 4-5)

67%

61%

ns

56%

< 0.001

50%

< 0.001

ns

2. Practice better hygiene (score 4-5)

91%

88%

ns

89%

ns

88%

ns

ns

ns

3. Avoid regions/persons¥ with new flu (score 4-5)

89%

78%

< 0.001

64%

< 0.001

66%

< 0.001

4. Wear face mask (score 4-5)

71%

60%

< 0.001

50%

< 0.001

47%

< 0.001

5. Seek medical advice with the onset of flu symptoms (score 4-5)

91%

87%

0.05

87%

0.02

86%

ns

ns

6. Take antiviral medication (score 4-5)

80%

80%

ns

71%

0.001

70%

< 0.001

ns

7. Stay home from school or work (score 4-5)

56%

50%

ns

52%

ns

50%

ns

ns

ns

8. Get a new vaccine against the new flu (score 4-5)

-

79%

-

69%

-

70%

< 0.001

Summary score items 1-7 (high) - Chronbach alpha 0.9

55%

43%

< 0.001

38%

< 0.001

35%

0.001









Intention* (scale 1-5; certainly not-certainly)

1. Keep away from crowded places (score 4-5)

76%

66%

0.001

62%

< 0.001

59%

0.001

2. Practice better hygiene (score 4-5)

93%

89%

ns

91%

ns

89%

ns

ns

ns

3. Avoid regions/persons¥ with new flu (score 4-5)

89%

81%

0.001

71%

< 0.001

72%

< 0.001

4. Wear face mask (score 4-5)

70%

57%

< 0.001

46%

< 0.001

44%

< 0.001

5. Seek medical advice with the onset of flu symptoms (score 4-5)

91%

89%

ns

84%

< 0.001

84%

0.01

ns

6. Take antiviral medication (score 4-5)

82%

76%

0.02

66%

< 0.001

65%

< 0.001

7. Stay home from school or work (score 4-5)

61%

53%

0.01

56%

ns

50%

ns

ns

8. Get a new vaccine against the new flu§ (score 4-5)

-

77%

-

67%

-

63%

0.001

Summary score items 1-7 (high) - Chronbach alpha 0.9

60%

48%

< 0.001

41%

< 0.001

41%

0.006









Maladaptive response (scale 1-5; totally disagree-totally agree)

The threat is exaggerated by media and government (score 4-5)

-

35%

-

56%

-

58%

< 0.001

+

It will not be as bad as predicted (score 4-5)

-

28%

-

49%

-

49%

< 0.001

+

Summary score - underestimation statements (high) - Chronbach alpha 0.6

-

20%

-

40%

-

42%

< 0.001

+

There is nothing we can do about it (score 4-5)

-

5%

-

14%

-

16%

< 0.001

+

We will all be completely powerless (score 4-5)

-

7%

-

14%

-

14%

< 0.001

+

We will just have to accept it (score 4-5)

-

24%

-

43%

-

47%

< 0.001

+

Summary score - fatalism statements (score 4-5) - Chronbach alpha 0.6

-

26%

-

48%

-

44%

< 0.001

+

I will move to a place without influenza (score 4-5)

-

2%

-

1%

-

0%

0.04

I will stock up and stay indoors (score 4-5)

-

3%

-

2%

-

4%

ns

ns

Summary score - avoidance statements (high) - Chronbach alpha 0.7

-

52%

-

39%

-

38%

< 0.001









Information (scale 1-5)

Amount of information received (score 4-5, much-very much)

52%

37%

< 0.001

53%

ns

48%

< 0.001

+

Attention paid to information received (score 4-5, much-very much)

30%

21%

0.002

21%

< 0.001

23%

ns

ns

Is information of the government reliable? (score 4-5, reliable-very reliable)

62%

53%

0.004

48%

< 0.001

45%

0.002

Is information of the government sufficient? (score 4-5, sufficient-very sufficient)

58%

42%

< 0.001

52%

0.02

47%

ns

ns









Measures taken

Practiced better hygiene

8%

12%

ns

36%

< 0.001

36%

< 0.001

ns

+

Avoided persons with influenza-like symptoms

-

4%

-

10%

-

9%

< 0.001

+

Avoided crowded places

3%

3%

ns

7%

0.003

8%

< 0.001

ns

+

Cancelled or did not book a holiday to areas with the new flu

0.2%

0.4%

ns

0.9%

ns

1%

ns

ns

ns

Bought face mask

0.4%

1%

ns

0.7%

ns

2%

ns

ns

ns

Bought antiviral medication

0.2%

0.4%

ns

0.4%

ns

2%

ns

ns

ns

Something else

1%

2%

ns

2%

ns

1%

ns

ns

ns

Summary score (any measures taken)

11%

14%

ns

40%

< 0.001

38%

< 0.001

ns

+


vs = versus; p-value obtained using Chi2 tests; p-value obtained using McNemar tests; τ follow-up of survey 1; π follow-up of survey 2; '-' data not collected in survey 1;

'+' indicates a significant increase over time; '—' indicates a significant decrease over time; ns = not statistically significant.

¥ In the third survey 'avoiding regions with Influenza A (H1N1)' was changed into 'avoiding persons with influenza like symptoms'.

* Respondents were asked to imagine that governmental health institutes would recommend the preventive behaviour.

§ A vaccine against Influenza A (H1N1) became available in the Netherlands in November 2009.

Bults et al. BMC Public Health 2011 11:2   doi:10.1186/1471-2458-11-2

Open Data