Selection of the Most Accurate Thermometer Devices for Clinical Practice: Part 1

Meta-Analysis of the Accuracy of Non-Core Thermometer Devices Compared to Core Body Temperature

Nancy A. Ryan-Wenger; Maureen A. Sims; Rebecca A. Patton; Jayme Williamson


Pediatr Nurs. 2018;44(3):116-133. 

In This Article

Abstract and Introduction


The literature is inconclusive on the accuracy of various thermometer devices used in clinical practice. We conducted a meta-analysis on the accuracy of temperatures from six peripheral (non-core) thermometer devices compared to core body temperature. Medline, CINAHL, and other resources were searched for articles related to body temperature and thermometer devices. From 197 articles, 159 were research and 38 were non-research. Thirty-four research articles met criteria for inclusion in the meta-analysis: core and non-core temperatures measured concurrently or sequentially, appropriate statistics, and sample size of 10 or more. We applied Cochrane GRADE criteria for diagnostic tests and strategies. Assessments of bias, indirectness of evidence, overall confidence in effect sizes, consistency, precision, and publication bias indicated low risk. The extent of heterogeneity was Q=0% for each type of thermometer device; impact of heterogeneity was 0% due to true differences, and I2=100% due to random sampling error. Forest plots illustrated bias (mean differences), 95% confidence limits, and confidence intervals (CI). A forest plot of the overall accuracy of non-core devices indicated that oral and rectal electronic thermometers had the least bias (−0.05°C and −0.04°C) and narrowest CI: oral=0.58°C, rectal=1.18°C, compared to temporal (1.88°C), axillary chemical (2.25°C), axillary electronic (2.36°C), and tympanic (2.62°C). Our findings indicate that only oral and rectal electronic thermometer devices should be used to measure temperature of individuals for screening, monitoring, diagnostic, and treatment decisions. Tympanic, temporal, axillary chemical, and axillary electronic thermometer devices should not be used in clinical practice.


Although the use of rectal and oral thermometers has been standard practice in pediatric and adult health-care settings, the quest for less invasive and more rapid methods of measuring body temperatures is expanding. The Global Body Temperature Monitoring Devices Market (Research and Markets, 2017) is expected to grow at a compounded rate of 5.33% between 2016 and 2021. Research and development to produce new and better, easier and less invasive digital and infrared devices are expanding due to risks posed by traditional mercury thermometers, increased prevalence of infectious diseases, the rise in population, and a concomitant increase in the number of hospitals and clinics. Although new thermometer devices are carefully tested for precision and accuracy in controlled laboratory settings, they often fall short when used in daily clinical practice. It is essential that thermometer devices yield precise and accurate temperatures for screening, monitoring, treatment decisions, and patient safety.

In numerous clinical studies, temperatures from thermometer devices were compared with temperatures from other devices or core body temperature, with mixed results on precision, accuracy, and recommendations for practice. Systematic reviews and meta-analyses of published studies can be valuable to sort out strengths and limitations of various non-core thermometer devices and inform changes in clinical practice. However, 10 systematic reviews/meta-analyses conducted between 1996 and 2016 on the accuracy of non-core thermometer devices provided data that are not useful for making practice change decisions.