Table 1 Descriptive characteristics of all calendar variables.

From: Prediction of emergency department presentations for acute coronary syndrome using a machine learning approach

Calendar data

Median [Q1–Q3] daily ED presentations

Variable

ACS

UA

NSTEMI

STEMI

Day of the weeka (H − statistic with df:6)

1169.98; p < 0.001

462.23; p < 0.001

611.02; p < 0.001

53.71; p < 0.001

 Monday

110 [97–123]

37 [29–52]

33 [28–39]

15 [13–18]

 Tuesday

90 [80–103]

31 [24–45]

28 [23–33]

14 [11–17]

 Wednesday

87 [77–96]

30 [23–42]

27 [23–31]

14 [11–16]

 Thursday

89 [77–98]

30 [23–42]

27 [22–32]

14 [11–16]

 Friday

88 [79–98]

28 [23–43]

28 [23–33]

14 [11–17]

 Saturday

67 [59–76]

20 [15–30]

22 [18–26]

14 [11–17]

 Sunday

69 [61–80]

21 [17–31]

23 [19–27]

14 [12–17]

Monthsa (H − statistic with df:11)

136.11; p < 0.001

50.56; p < 0.001

100.15; p < 0.001

94.71; p < 0.001

 January

91 [75–104]

30 [23–47]

27.5 [22–33]

15 [12–17]

 February

89 [76–104]

28.5 [23–43]

28 [23–32]

15 [12–17]

 March

91 [79–106]

31 [24–44]

28 [22–34]

15 [12–18]

 April

89 [75–104]

30 [22–43]

28 [23–33]

15 [12–18]

 May

83 [71–95]

30 [20–41]

26 [21–32]

14 [12–17]

 June

83 [69–98]

28 [21–41]

26 [20–31]

14 [11–16]

 July

78 [64–89]

27 [20–38]

24 [19–28]

13 [10–15]

 August

77 [66–89]

26 [19–37]

23 [20–28]

13 [10–16]

 September

85 [73–100]

28 [21–40]

27 [22–32]

14 [11–16]

 October

86 [75–97]

29 [21–41]

27 [23–32]

14 [12–17]

 November

88 [74–99]

29 [21–40]

27 [22–34]

14 [12–18]

 December

84 [69–96]

26 [19–36]

27 [22–32]

14 [11–17]

Seasona (H − statistic with df:3)

90.0 p < 0.001

18.6 p < 0.001

80.7 p < 0.001

81.1 p < 0.001

 Winter

88 [74–101]

29 [21 − 40.25]

27 [22–32]

15 [12–17]

 Spring

88 [73–103]

30 [22–42]

27 [22–32]

15 [12–18]

 Summer

79 [66–92]

27 [20–38]

27 [22–32]

13 [10–16]

 Autumn

86 [74–99]

29 [21–40]

24 [20–29]

14 [12–17]

Yeara (H − statistic with df: 7)

293.67; p < 0.001

1744.44; p < 0.001

596.47; p < 0.001

44.28; p < 0.001

 2010

96 [82–110]

52 [44–60]

22 [18–26]

14 [11–17]

 2011

97 [84–110]

51 [43–60]

23 [19–27]

14 [12–17]

 2012

81 [69–94]

33 [27–40]

24 [20–28]

13 [11–16]

 2013

83 [70–95]

29 [23–35]

27 [22–31]

14 [11–17]

 2014

82 [69–94]

25 [20–30]

28 [23–33]

14 [10–16]

 2015

80 [67–92]

23 [19–28]

28 [24–34]

15 [12–18]

 2016

85 [71–97]

23 [18–27]

31 [26–36]

15 [12–18]

 2017

81 [68–95]

19 [15–23]

31 [26–36]

14 [12–17]

  1. ACS Acute coronary syndrome, CI Confidence Interval, df degrees of freedom, UA unstable angina pectoris, NSTEMI non ST − elevated myocardial infarction, STEMI ST − elevated myocardial infarction, NA Not applicable, °C degrees Celsius, h hour, J/cm2 Joule per square centimeter as measure of surface tension, hPa hectopascal, mm millimeters, m/s meter per second.
  2. aCalendar data Day of the week, Month, Season, and Year are analyzed using Kruskal − Wallis test with H − statistics as output. Consequently, post hoc Dunn’s tests with Bonferroni correction were performed with the first category Monday, January, Winter and 2010 as reference categories.
  3. Bold indicates significance (p < 0.05).
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