Summary statistics for bibliometrics
| Quantitative n=126 | Qualitative n=42 | P value | |
| Citation number, median (IQR) | |||
| Web of Science | 62 (38–111) | 58 (36–85) | 0.47 |
| Scopus | 78 (45–131) | 74 (48–105) | 0.52 |
| Google Scholar | 121.5 (68–203) | 134 (85–185) | 0.98 |
| ProQuest Altmetric | 88 (52–151) | 73 (44–113) | 0.16 |
| Scopus Field Weighted Citation Impact, median (IQR) | 7.06 (4.58–12) | 5.96 (4.33–10.26) | 0.16 |
| Scopus Citation Percentile, median (IQR) | 93 (84–97) | 91 (86–95) | 0.21 |
Citation numbers are different between Scopus, Web of Science, Google Scholar and ProQuest Altmetric as each platform collects citation information differently. Web of Science covers the oldest citations, from 1900 to present.52 Scopus covers citations starting in 1966, but it indexes a larger number of journals including a greater number of international and open access journals as compared with Web of Science. Google Scholar and ProQuest Altmetric do not reveal information on their method of citation collection.44 ProQuest Altmetric uses a novel research insight platform called Dimensions which captures references beyond classic publication-based citations.53 The platform developers state that Dimensions is not comparable to Web of Science, Google Scholar or Scopus, though no further information is provided.