Reexamining age, race, site, and thermometer type as variables affecting temperature measurement in adults - A comparison study

Abstract

BACKGROUND: As a result of the recent international vigilance regarding disease assessment, accurate measurement of body temperature has become increasingly important. Yet, trusted low-tech, portable mercury glass thermometers are no longer available. Thus, comparing accuracy of mercury-free thermometers with mercury devices is essential. Study purposes were 1) to examine age, race, site as variables affecting temperature measurement in adults, and 2) to compare clinical accuracy of low-tech Galinstan-in-glass device to mercury-in-glass at oral, axillary, groin, and rectal sites in adults. METHODS: Setting 176 bed accredited healthcare facility, rural northwest USParticipants Convenience sample (N = 120) of hospitalized persons GreaterEqual; 18 years old.Instruments Temperatures ( degrees F) measured at oral, skin (simultaneous), immediately followed by rectal sites with four each mercury-glass (BD) and Galinstan-glass (Geratherm) thermometers; 10 minute dwell times. RESULTS: Participants averaged 61.6 years (SD 17.9), 188 pounds (SD 55.3); 61% female; race: 85% White, 8.3% Native Am., 4.2% Hispanic, 1.7 % Asian, 0.8% Black. For both mercury and Galinstan-glass thermometers, within-subject temperature readings were highest rectally; followed by oral, then skin sites. Galinstan assessments demonstrated rectal sites 0.91 degrees F > oral and FullEqual; 1.3 degrees F > skin sites. Devices strongly correlated between and across sites. Site difference scores between devices showed greatest variability at skin sites; least at rectal site. 95% confidence intervals of difference scores by site ( degrees F): oral (0.142 - 0.265), axilla (0.167 - 0.339), groin (0.037 - 0.321), and rectal (-0.111 - 0.111). Race correlated with age, temperature readings each site and device. CONCLUSION: Temperature readings varied by age, race. Mercury readings correlated with Galinstan thermometer readings at all sites. Site mean differences between devices were considered clinically insignificant. Still considered the gold standard, mercury-glass thermometers may no longer be available worldwide. Therefore, mercury-free, environmentally safe low-tech Galinstan-in-glass may be an appropriate replacement. This is especially important as we face new, internationally transmitted diseases.

Figure 1

Box plot showing mean temperature reading differences and variability between mercury-in-glass and Galinstan-in-glass devices at four sites (°F). Box plot – mean differences by site Mercury/Galinstan pairs

Figure 2

Scatter plot – devices by site (°F). Scatter plot – devices by site Mercury/Galinstan pairs o – oral x-axilla g-groin r-rectal hg-Mercury-in-glass gal-Galinstan-in glass

Figure 3

Scatter plot of differences, at the oral site, against their mean (°F). The mean difference (mercury minus Galinstan) is 0.20°F, SD 0.34, skewness 0.676. Oral Device differences against their means _________ mean difference, mercury-Galinstan - - - - - - 2 SDs from the mean

Figure 4

Scatter plot of differences, axilla site, against their mean (°F). The mean difference (mercury minus Galinstan) is 0.25°F, SD 0.48, skewness 0.396. Axilla Device differences against their mean _________ mean difference, mercury-Galinstan - - - - - - 2 SDs from the mean

Figure 5

Scatter plot of differences, at the groin site, against their mean (°F). The mean difference (mercury minus Galinstan) is 0.18°F, SD 0.79, and skewness -0.075. Groin Device differences against their means _________ mean difference, mercury-Galinstan - - - - - - 2 SDs from the mean

Figure 6

Scatter plot of differences, at the rectal site, against their mean (°F). The mean difference (mercury minus Galinstan) is -0.06°F, SD 0.31, and skewness -1.04. Rectal Device differences against their means _________ mean difference, mercury-Galinstan - - - - - - 2 SDs from the mean