. Author manuscript; available in PMC: 2009 Jan 1.

Published in final edited form as: Int J Osteopath Med. 2008;11(2):62–68. doi: 10.1016/j.ijosm.2008.03.003

Table 1.

Somatic dysfunction in type 2 diabetes.^*

Sensitivity = a/(a + c) = 47/62 = 76%

Specificity = d/(b + d) = 17/29 = 59%

Positive predictive value = a/(a + b) = 47/59 = 80%

Negative predictive value = d/(c + d) = 17/32 = 53%

LR+ = sensitivity/(100% − specificity) = 76%/41% = 1.85

LR− = (100% − sensitivity)/specificity = 24%/59% = 0.41

Pre-test likelihood of somatic dysfunction = 173/1199 = 14%

Pre-test odds of somatic dysfunction = pre-test probability/(100% − pre-test probability) = 14%/86% = 16%

Post-test odds of somatic dysfunction (+ test) = pre-tests odds × LR+ = 16% × 1.85 = 30%

Post-test odds of somatic dysfunction (− test) = pre-test odds × LR− = 16% × 0.41 = 7%

Post-test likelihood of somatic dysfunction (+ test) = post-test odds/(post-test odds + 100%) = 30%/130% = 23%

Post-test likelihood of somatic dysfunction (− test) = post test odds/(post-test odds + 100%) = 7%/107% = 7%

Data refer type 2 diabetes as a "diagnostic test" for tissue texture changes at T11-L2 on the right side. LR denotes likelihood ratio. Pre-test likelihood of somatic dysfunction is based on Licciardone, Nelson, Glonek, Sleszynski, and Cruser.²⁸