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Table 1 Baseline characteristics of the United States appendicitis patients presenting to the ED NHAMCS 2005–2017

From: Prediction of acute appendicitis among patients with undifferentiated abdominal pain at emergency department

  All Adult N(%) Adult Appendicitis N(%) Adult Non-appendicitis N(%) p-value1 All Pediatric N(%) Pediatric Appendicitis N(%) Pediatric Non-appendicitis N(%) p-value1
28657(100.0) 655(2.3) 28002(97.7)   11384(100.0) 256(2.2) 11128(97.8)  
Sex Female 19052(66.5) 317(1.7) 18735(98.3) < 0.001 5877(51.6) 88(1.5) 5789(98.5) < 0.001
Male 9605(33.5) 338(3.5) 9267(96.5) 5507(48.4) 168(3.1) 5339(96.9)
Age 44.16±19.61 38.24±15.97 44.30±19.66 < 0.001 5.69±5.42 10.72±3.97 5.57±5.39 < 0.001
Ethnicity Hispanic or Latino 4769(16.6) 137(2.9) 4632(97.1) 0.003 3494(30.7) 85(2.4) 3409(97.6) 0.378
Not Hispanic or Latino 23888(83.4) 518(2.2) 23370(97.8) 7890(69.3) 171(2.2) 7719(97.8)
Race White 21993(76.7) 550(2.5) 21443(97.5) < 0.001 8213(72.1) 225(2.7) 7988(97.3) < 0.001
Black/African American 5577(19.5) 62(1.1) 5515(98.9) 2590(22.8) 20(0.8) 2570(99.2)
Asian 617(2.2) 27(4.4) 590(95.6) 304(2.7) 6(2.0) 298(98.0)
Native Hawaiian/Other Pacific Islander 171(0.6) 6(3.5) 165(96.5) 107(0.9) 2(1.9) 105(98.1)
American Indian/Alaska Native 188(0.7) 8(4.3) 180(95.7) 88(0.8) 1(1.1) 87(98.9)
More than one race reported 111(0.4) 2(1.8) 109(98.2) 82(0.7) 2(2.4) 80(97.6)
Residence Private residence 27749(96.8) 644(2.3) 27105(97.7) 0.004 11318(99.4) 254(2.2) 11064(97.8) 0.646
Nursing home 466(1.6) 1(0.2) 465(99.8) 15(0.1) 0(0.0) 15(100.0)
Homeless/homeless shelter 134(0.5) 0(0.0) 134(100.0) 8(0.1) 0(0.0) 8(100.0)
Other 308(1.1) 10(3.2) 298(96.8) 43(0.4) 2(4.7) 41(95.3)
Insurance Private insurance 9942(34.7) 372(3.7) 9570(96.3) < 0.001 3342(29.4) 122(3.7) 3220(96.3) < 0.001
Medicare 6351(22.2) 64(1) 6287(99.0) 147(1.3) 2(1.4) 145(98.6)
Medicaid or CHIP or other state-based program 7494(26.2) 111(1.5) 7383(98.5) 6990(61.4) 110(1.6) 6880(98.4)
Worker’s compensation 41(0.1) 2(4.9) 39(95.1) 2(0.0) 0(0.0) 2(100.0)
Self-pay 3818(13.3) 87(2.3) 3731(97.7) 666(5.9) 15(2.3) 651(97.7)
No charge/Charity 312(1.1) 9(2.9) 303(97.1) 26(0.2) 0(0.0) 26(100.0)
Other 699(2.4) 10(1.4) 689(98.6) 211(1.9) 7(3.3) 204(96.7)
Visit year 2005 1988(6.9) 69(3.5) 1919(96.5) < 0.001 538(4.7) 31(5.8) 507(94.2) < 0.001
2006 2079(7.3) 67(3.2) 2012(96.8) 767(6.7) 28(3.7) 739(96.3)
2007 2248(7.8) 67(3.0) 2181(97.0) 593(5.2) 18(3.0) 575(97.0)
2008 2244(7.8) 58(2.6) 2186(97.4) 594(5.2) 23(3.9) 571(96.1)
2009 2452(8.6) 56(2.3) 2396(97.7) 1270(11.2) 27(2.1) 1243(97.9)
2010 2716(9.5) 64(2.4) 2652(97.6) 1231(10.8) 13(1.1) 1218(98.9)
2011 2569(9.0) 71(2.8) 2498(97.2) 1038(9.1) 23(2.2) 1015(97.8)
2012 2543(8.9) 55(2.2) 2488(97.8) 1025(9.0) 22(2.1) 1003(97.9)
2013 2200(7.7) 28(1.3) 2172(98.7) 911(8.0) 20(2.2) 891(97.8)
2014 2207(7.7) 37(1.7) 2170(98.3) 1094(9.6) 17(1.6) 1077(98.4)
2015 1942(6.8) 27(1.4) 1915(98.6) 826(7.3) 15(1.8) 811(98.2)
2016 1870(6.5) 34(1.8) 1836(98.2) 782(6.9) 6(0.8) 776(99.2)
2017 1599(5.6) 22(1.4) 1577(98.6) 715(6.3) 13(1.8) 702(98.2)
Visit month January 2464(8.6) 59(2.4) 2405(97.6) 0.988 1058(9.3) 22(2.1) 1036(97.9) 0.009
February 2181(7.6) 48(2.2) 2133(97.8) 1018(8.9) 20(2.0) 998(98.0)
March 2408(8.4) 56(2.3) 2352(97.7) 987(8.7) 16(1.6) 971(98.4)
April 2432(8.5) 51(2.1) 2381(97.9) 966(8.5) 16(1.7) 950(98.3)
May 2480(8.7) 58(2.3) 2422(97.7) 1006(8.8) 22(2.2) 984(97.8)
June 2385(8.3) 57(2.4) 2328(97.6) 892(7.8) 17(1.9) 875(98.1)
July 2468(8.6) 61(2.5) 2407(97.5) 841(7.4) 16(1.9) 825(98.1)
August 2641(9.2) 60(2.3) 2581(97.7) 893(7.8) 22(2.5) 871(97.5)
September 2394(8.4) 58(2.4) 2336(97.6) 958(8.4) 38(4.0) 920(96.0)
October 2167(7.6) 50(2.3) 2117(97.7) 890(7.8) 31(3.5) 859(96.5)
November 2402(8.4) 45(1.9) 2357(98.1) 976(8.6) 18(1.8) 958(98.2)
December 2235(7.8) 52(2.3) 2183(97.7) 899(7.9) 18(2.0) 881(98.0)
Visit day Sunday 3926(13.7) 83(2.1) 3843(97.9) 0.469 1812(15.9) 38(2.1) 1774(97.9) 0.451
Monday 4498(15.7) 90(2.0) 4408(98.0) 1808(15.9) 37(2.0) 1771(98.0)
Tuesday 4229(14.8) 107(2.5) 4122(97.5) 1637(14.4) 29(1.8) 1608(98.2)
Wednesday 4201(14.7) 102(2.4) 4099(97.6) 1508(13.2) 44(2.9) 1464(97.1)
Thursday 4081(14.2) 91(2.2) 3990(97.8) 1558(13.7) 39(2.5) 1519(97.5)
Friday 3879(13.5) 100(2.6) 3779(97.4) 1460(12.8) 33(2.3) 1427(97.7)
Saturday 3843(13.4) 82(2.1) 3761(97.9) 1601(14.1) 36(2.2) 1565(97.8)
Arrival time Morning 7966(27.8) 195(2.4) 7771(97.6) 0.697 2435(21.4) 53(2.2) 2382(97.8) 0.136
Afternoon 8027(28.0) 178(2.2) 7849(97.8) 2605(22.9) 74(2.8) 2531(97.2)
Evening 6111(21.3) 133(2.2) 5978(97.8) 2993(26.3) 61(2.0) 2932(98.0)
Night 6553(22.9) 149(2.3) 6404(97.7) 3351(29.4) 68(2.0) 3283(98.0)
Temperature 36.78±0.59 36.92±0.64 36.77±0.58 < 0.001 37.44±1.06 37.18±0.83 37.45±1.06 < 0.001
Triage level Immediate 375(1.3) 21(5.6) 354(94.4) < 0.001 80(0.7) 8(10.0) 72(90.0) < 0.001
Emergent 2353(8.2) 82(3.5) 2271(96.5) 607(5.3) 32(5.3) 575(94.7)
Urgent 20269(70.7) 483(2.4) 19786(97.6) 5854(51.4) 170(2.9) 5684(97.1)
Semi-urgent 4677(16.3) 57(1.2) 4620(98.8) 4166(36.6) 38(0.9) 4128(99.1)
Nonurgent 983(3.4) 12(1.2) 971(98.8) 677(5.9) 8(1.2) 669(98.8)
Is injury/poisoning intentional Intentional 145(0.5) 2(1.4) 143(98.6) < 0.001 19(0.2) 0(0.0) 19(100) 0.007
Unintentional 2113(7.4) 12(0.6) 2101(99.4) 480(4.2) 1(0.2) 479(99.8)
Questionable injury status 26399(92.1) 641(2.4) 25758(97.6) 10885(95.6) 255(2.3) 10630(97.7)
Visit related to an injury/poison/adverse effect of medical treatment with in 72 hours No 26123(91.2) 644(2.5) 25479(97.5) < 0.001 10831(95.1) 256(2.4) 10575(97.6) 0.001
Yes 2534(8.9) 11(0.5) 2523(99.5) 553(4.9) 0(0.0) 553(100.0)
Systolic blood pressure 134.17±22.87 130.93±19.10 134.24±22.94 0.190 110.53±14.20 117.16±15.25 110.38±14.14 0.003
Diastolic blood pressure 78.62±18.28 76.76±12.11 78.67±18.40 < 0.001 69.16±49.87 67.43±12.34 69.20±50.40 < 0.001
Pulse Oximetry 87.66±17.99 87.38±19.08 87.66±17.96 < 0.001 120.70±31.04 103.63±23.95 121.10±31.08 < 0.001
72h Revisit Yes 1394(4.9) 22(1.6) 1372(98.4) 0.070 448(3.9) 10(2.2) 438(97.8) 0.981
No 27263(95.1) 633(2.3) 26630(97.7) 10936(96.1) 246(2.2) 10690(97.8)
Pain level Mild 5711(19.9) 62(1.1) 5649(98.9) < 0.001 6337(55.7) 36(0.6) 6301(99.4) < 0.001
Moderate 9496(33.1) 226(2.4) 9270(97.6) 3210(28.2) 116(3.6) 3094(96.4)
Very severe 13450(46.9) 367(2.7) 13083(97.3) 1837(16.1) 104(5.7) 1733(94.3)
Diagnostic services provided No 3665(12.8) 47(1.3) 3618(98.7) < 0.001 3944(34.6) 21(0.5) 3923(99.5) < 0.001
Yes 24992(87.2) 608(2.4) 24384(97.6) 7440(65.4) 235(3.2) 7205(96.8)
  1. Missing value for patient’s residence type, diagnostic services provided, arrival time, body temperature and whether the visit is related to injury/poisoning is lower than 5%. Missing values for source of payment, pulse oximetry are between 5 and 10%. Missing value for race, heart rate, 72 h revisit, systolic and diastolic blood pressure are between 10 and 15%. Missing value for ethnicity and triage level are 15 and 20%. Missing value for pain level is 24.89%. Missing value for is injury/poisoning intentional is 43.20%
  2. Note: 1p-values in this table came from the chi-squared test for categorical variables and from the t-test for continuous variables