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Table 3 Data quality and item-total correlations for ASTA symptom scale

From: Development and validation of a new Arrhythmia-Specific questionnaire in Tachycardia and Arrhythmia (ASTA) with focus on symptom burden

Items Symptom scale 10 items1 Symptom scale 9 items1 Answer alternatives2
Symptoms in connection with arrhythmia Item-total correlation Cronbach´s α if item deleted MeanSD1 Item-total corr elation Cronbach´s α if item deleted MeanSD1 “No”n(%) “Yes, to a certain extent” n(%) “Yes, quite a lot” n(%) “Yes, a lot” n(%)
Breathlessness during activity 0.496 0.808 1.79(0.98) 0.479 0.777 1.79(0.98) 24(9) 75(28) 73(27) 70(26)
Breathlessness even at rest 0.569 0.801 0.77(0.81) 0.588 0.762 0.77(0.81) 105(39) 107(40) 22(8) 11(4)
Dizziness 0.468 0.810 0.86(0.79) 0.465 0.778 0.86(0.79) 87(32) 116(43) 33(12) 10(4)
Cold sweat 0.455 0.813 0.97(0.98) 0.450 0.781 0.97(0.98) 100(37) 76(28) 48(18) 22(8)
Pronounced tiredness 0.604 0.795 1.74(0.98) 0.544 0.767 1.74(0.98) 26(10) 75(28) 79(29) 65(24)
Chest pain 0.431 0.814 0.56(0.74) 0.465 0.778 0.56(0.74) 134(50) 91(34) 14(5) 7(3)
Pressure/discomfort in chest 0.428 0.814 1.01(0.88) 0.461 0.778 1.01(0.88) 74(27) 116(43) 37(14) 18(7)
Worry 0.367 0.820 1.29(0.86) 0.348 0.793 1.29(0.86) 39(14) 125(46) 57(21) 27(10)
Weakness 0.650 0.792 1.54(0.86) 0.585 0.762 1.54(0.86) 21(8) 115(43) 73(27) 38(14)
Infirmity 0.609 0.795 1.67(0.92) - - - 21(8) 93(34) 80(30) 53(20)
   Cronbach´s α0.822 12.18(5.48)   Cronbach´s α0.795 10.51(4.88)     
  1. 1 n = 230.
  2. 2 n = 242–247, the number of missing answers varied between 23–28 for the different items in the 10 item scale.