Table 4.
Most frequently study keywords in palliative care by years
| Rank | Keyword | 2002–2008 | 2009–2014 | 2015–2020 | Total 2002–31 December, 2020 | ||||
| Occurrences | Total link strength | Occurrences | Total link strength | Occurrences | Total link strength | Occurrences | Total link strength | ||
| 1 | Cancer | 71 | 273 | 519 | 993 | 1073 | 1823 | 1933 | 3028 |
| 2 | Paediatric | 14 | 54 | 171 | 274 | 428 | 581 | 667 | 865 |
| 3 | Quality of life | 19 | 76 | 186 | 404 | 327 | 632 | 624 | 1102 |
| 4 | Pain | 29 | 121 | 190 | 416 | 272 | 444 | 565 | 935 |
| 5 | Qualitative research | 11 | 48 | 128 | 275 | 361 | 692 | 538 | 962 |
| 6 | Education | 21 | 74 | 111 | 223 | 285 | 476 | 462 | 750 |
| 7 | Heart problems | 17 | 56 | 130 | 161 | 247 | 253 | 440 | 421 |
| 8 | Home care | 12 | 54 | 112 | 236 | 258 | 533 | 439 | 817 |
| 9 | Nursing | 5 | 24 | 127 | 292 | 236 | 490 | 418 | 836 |
| 10 | Radiotherapy | 16 | 49 | 110 | 172 | 192 | 222 | 399 | 472 |
| 11 | Caregivers | 12 | 54 | 83 | 195 | 265 | 539 | 394 | 740 |
| 12 | Older people | 9 | 35 | 110 | 247 | 210 | 433 | 369 | 699 |
| 13 | Death and dying | 22 | 85 | 100 | 234 | 170 | 346 | 363 | 693 |
| 14 | Communication | 4 | 16 | 112 | 249 | 212 | 427 | 351 | 675 |
| 15 | Chemotherapy | 11 | 45 | 90 | 121 | 165 | 206 | 295 | 341 |