Temperature measurements with a temporal scanner: systematic review and meta-analysis

OBJECTIVES: Systematic review and meta-analysis on the diagnostic accuracy of temporal artery thermometers (TAT). DESIGN: Systematic review and meta-analysis. The index test consisted of temperature measurement with TAT. The reference test consisted of an estimation of core temperature. PARTICIPANTS: Clinical patients as well as healthy participants, with or without fever. INTERVENTIONS: Literature search in PubMed, Embase, Cinahl and Web of Science. Three reviewers selected articles for full-text reading after which a further selection was made. Risk of bias was assessed with QUADAS-2. Pooled difference and limits of agreement (LoA) were estimated with an inverse variance weighted approach. Subgroup and sensitivity analyses were performed. Sensitivity and specificity were estimated using hierarchical models. Quality of evidence was assessed according to the GRADE system. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was measurement accuracy expressed as mean difference ±95% LoA. A secondary outcome was sensitivity and specificity to detect fever. If tympanic thermometers were assessed in the same population as TAT, these results were recorded as well. RESULTS: 37 articles comprising 5026 participants were selected. Pooled difference was -0.19°C (95% LoA −1.16 to 0.77°C), with moderate quality of evidence. Pooled sensitivity was 0.72 (95% CI 0.61 to 0.81) with a specificity of 0.94 (95% CI 0.87 to 0.97). The subgroup analysis revealed a trend towards underestimation of the temperature for febrile patients. There was a large heterogeneity among included studies with wide LoA which reduced the quality of evidence. CONCLUSIONS: TAT is not sufficiently accurate to replace one of the reference methods such as rectal, bladder or more invasive temperature measurement methods. The results are, however, similar to those with tympanic thermometers, both in our meta-analysis and when compared with others. Thus, it seems that TAT could replace tympanic thermometers with the caveat that both methods are inaccurate. TRIAL REGISTRATION NUMBER: CRD42014008832.