Translation and validation of the Nepean Dyspepsia Index for functional dyspepsia in China

Table 1 Internal consistency of items in each domain

Factor	Domain	Cronbach’s α
1	Interference	0.944
2	Know/control	0.906
3	Eat/drink	0.833
4	Sleep disturb	0.960

Table 2 Pearson item-dimension correlation coefficients

Item	Domains
	Interference	Know/control	Eat/drink	Sleep disturb
01	0.626	0.531	0.461	0.354
02	0.701	0.817	0.450	0.376
03	0.666	0.812	0.492	0.396
04	0.522	0.493	0.906	0.457
05	0.457	0.476	0.840	0.454
06	0.589	0.484	0.852	0.389
07	0.473	0.476	0.472	0.982
08	0.511	0.536	0.509	0.980
09	0.822	0.640	0.521	0.464
10	0.828	0.638	0.520	0.399
11	0.826	0.677	0.455	0.437
12	0.818	0.635	0.446	0.403
13	0.815	0.568	0.482	0.342
14	0.800	0.575	0.432	0.397
15	0.794	0.564	0.471	0.289
16	0.771	0.715	0.467	0.442
17	0.753	0.832	0.424	0.430
18	0.742	0.843	0.505	0.528
19	0.746	0.774	0.482	0.374
20	0.824	0.827	0.554	0.458
21	0.751	0.624	0.477	0.370
22	0.557	0.771	0.368	0.347
23	0.506	0.710	0.362	0.321
24	0.709	0.814	0.527	0.487
25	0.631	0.577	0.327	0.294

Table 3 Rotated component matrix

Item	Component
	1	2	3	4
22	0.777	0.101	0.154
23	0.735		0.145
19	0.725	0.352	0.201
17	0.715	0.417		0.223
18	0.685	0.367	0.178	0.312
20	0.684	0.448	0.261	0.184
24	0.640	0.332	0.266	0.257
03	0.634	0.312	0.336
02	0.612	0.413	0.263
16	0.598	0.445	0.156	0.225
25	0.536	0.374
13	0.206	0.853	0.200
14	0.216	0.835	0.117	0.164
15	0.225	0.828	0.204
10	0.354	0.695	0.270	0.122
12	0.395	0.689	0.107	0.202
09	0.341	0.659	0.284	0.215
11	0.449	0.630	0.132	0.248
21	0.458	0.501	0.258	0.129
01	0.335	0.378	0.377	0.124
04	0.182	0.235	0.834	0.188
05	0.277		0.762	0.248
06	0.171	0.399	0.713
07	0.197	0.180	0.225	0.908
08	0.255	0.192	0.256	0.878