Table 3. Inter-item Pearson’s correlations for the FDSD items (N=57).
| FDSD item* | FDSD item number |
|||||||
|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
| 1. Stomach pain | 1.00 | — | — | — | — | — | — | — |
| 2. Burning in the stomach | 0.66 | 1.00 | — | — | — | — | — | — |
| 3. Nausea | 0.48 | 0.40 | 1.00 | — | — | — | — | — |
| 4. Bloating | 0.60 | 0.40 | 0.49 | 1.00 | — | — | — | — |
| 5. Stomach fullness | 0.61 | 0.34 | 0.62 | 0.69 | 1.00 | — | — | — |
| 6. Early satiety | 0.60 | 0.38 | 0.59 | 0.74 | 0.77 | 1.00 | — | — |
| 7. Burping/belching rating | 0.43 | 0.41 | 0.55 | 0.52 | 0.35 | 0.38 | 1.00 | — |
| 8. Burping/belching bother | 0.30 | 0.34 | 0.43 | 0.45 | 0.21 | 0.36 | 0.78 | 1.00 |
FDSD, Functional Dyspepsia Symptom Diary.
*FDSD items are scored on an 11-point numeric rating scale from 0 (no (concept)) to 10 (worst imaginable (concept)). Pearson’s correlation coefficients r>0.80 indicate items are capturing potentially redundant information (24).