The diagnostic accuracy of the squeeze test to identify arthritis: a cross-sectional cohort study.

Abstract

In daily practice, the squeeze test is used to screen for arthritis in metacarpophalangeal (MCP) and metatarsophalangeal (MTP) joints. This cross-sectional cohort study determined the diagnostic accuracy of this test. Patients referred with arthralgia of recent onset that had either a clinical suspicion for progression to arthritis or clinically apparent arthritis were studied. The main outcome was swelling at physical examination of ≥1 MCP or MTP joint. Joint inflammation detected at extremity MRI was the secondary outcome. Both at MCP and MTP joints, a positive squeeze test associated with swollen joints (p<0.005). The sensitivity of the test at the MCP joints was 53%, specificity 82%, positive likelihood ratio (LR+) 3.0, negative likelihood ratio (LR-) 0.6 and area under the receiver operator characteristic curve (AUC) 0.68. At the MTP joints, the sensitivity was 54%, specificity 74%, LR+ 2.1, LR- 0.6 and AUC 0.64. With MRI-detected inflammation as outcome, the sensitivity and specificity were 39% and 86% and 31% and 69% for the test at the MCP and MTP joints, respectively. A positive squeeze test is associated with local joint inflammation but the sensitivity is low, indicating a high percentage of swollen joints with a negative squeeze test. When the test is used on its own, it is insufficient to detect early arthritis.