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