The Trend to Use the Word "Trend" to Describe Nonsignificant Results in Orthopaedic Literature

Use of the word "trend" for statistical judgment with no statistical significance has been recognized in multiple fields of medical literature. "Trend" is sometimes used to describe "nearly significant" findings when they are not statistically significant. The purpose of this study was to characterize the use of the word "trend" to describe nonsignificant findings in orthopaedic publications.

Orthopaedic journals indexed in MEDLINE were identified using the terms: orthopedics OR orthopaedics OR sports medicine OR orthopedic OR orthopaedic. Abstracts from these journals that contained the word "trend" from 1985 to 2022 were identified. Journals containing literature on nonhuman orthopaedics were excluded. "Trend" used for statistical judgment without a p-value or with a nonsignificant p-value was labeled "NS Trend". Use of "trend" not in the context of statistical tests was labeled as "dictionary usage" of the word.

A total of 59,839 article abstracts were identified, with "trend" being used in 1,029 abstracts (1.7%). "NS Trend" was used in 617 abstracts (60%) to describe significant results when the p-value was not given or not actually significant. There was a strong correlation over time with increasing use of the word "trend" in orthopaedic abstracts (r = 0.956). An exponential rise in "NS Trend" usage was found (r = 0.924; R² = 0.853; p < 0.001). An exponential fit was confirmed using a Kolmogorov-Smirnov test (p = 0.283).

The word "trend" is increasingly being used in orthopaedic literature, including suggesting statistical significance when absent. Misinterpretation of statistical analyses can lead to research conclusions that push readers toward inappropriate treatments. It is imperative that we clearly communicate our statistical findings and not use ambiguous language. The word "trend" should only be used to describe an actual trend analysis and not to imply statistical significance when none is present.