A review of the use of likelihood ratios in the chiropractic literature.

Objective: The objective of this review is to determine how frequently likelihood ratios (LRs) have been used or described in the chiropractic literature and to depict their appropriate use in the clinical setting.

Methods: A literature search was conducted of the MEDLINE, Manual Alternative and Natural Therapy Index System, and Index to Chiropractic Literature databases, with search years encompassing 1966 through June 2006. Citations in the English language that addressed the following search terms were retrieved: likelihood ratio in combination with manipulation and chiropractic.

Results: The searches netted a total of 64 citations: 10 in MEDLINE, 34 in the Manual Alternative and Natural Therapy Index System, and 20 in the Index to Chiropractic Literature. After eliminating articles from journals that were not focused specifically on chiropractic, duplicates, and those that did not involve LRs, 3 articles remained and were reviewed. None of the reviewed articles provided a description of LRs, and only 2 used them in a clinical context.

Conclusions: The use of LRs can be very helpful in patient management; however, LRs are rarely reported in the chiropractic literature. Accordingly, chiropractic practitioners are most likely uninformed on the subject and may not have the capacity to use them in formulating diagnoses. It is suggested that researchers increase the reporting of LRs and that chiropractic clinicians begin to make use of them in day-to-day practice.