Comparative Evaluation of Non-Mercury Thermometers in a Hospital Setting

Rafic Hariri School of NursingJune 1, 2011

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BackgroundPurposeLiterature reviewResearch MethodsResultsRecommendationsLimitations

Outline

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Phasing out MERCURY

WHY???

Toxic

Pollutant

Bioaccumulative

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Phasing out MERCURY

Mercury in the atmosphere has increased 20 times since 1840

Human activities account for about 70% of the mercury emissions compared to natural sources

[Source: US Geological Survey, 2002]

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Phasing out MERCURYMercury Baseline Information from LEBANON (2001 –

2005)

Average Mass Imported (Kg Hg per year) 214

Quantity of Thermometers Imported 427517

Estimated Releases (Kg Hg per year) 31

Percentage Releases 14.5

United Nations Development Programme (August, 2007). UNDP project document: Government of Argentina, India, Latvia, Lebanon, Philippines, Senegal, Kingdom of Tanzania and Vietnam. Retrieved on November 20, 2010 from http://gefmedwaste.org/downloads/ProDoc.pdf

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WHO Policy on Mercury in Health

Care(August 2005)

Short Term: Address mercury clean up, waste handling and storage procedures. Develop and implement plans to reduce the use of mercury equipment and replace with mercury free alternatives.

Medium Term: Increase efforts to reduce use of unnecessary mercury equipment

Long Term: Support a ban of mercury containing devices and promote alternatives.

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Purpose

The objectives of the study are:

To determine the available thermometry technologies available in the Lebanese market and their cost effectiveness for a model healthcare facility.

To determine the suitability of use of two alternative thermometers in a hospital setting based on differences in their essential characteristics and preferences of healthcare professional staff.

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Literature incomprehensive and inconclusive

difficult for meta-analysis because studies target different patient populations and utilize a variety of devices

Overall, electronic thermometers have the widest support as reliable, accurate, and safe alternatives to mercury thermometers.

The problem is that they are thought to be expensive

Crawford, D. C., Hicks, B., & Thompson, M. J. (2006). Which thermometer? Factors influencing best choice for intermittent clinical temperature assessment. Journal of Medical Engineering & Technology, 30(4), 199 – 211.

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Research Methods Market survey

Nursing leadership preferences

Comparative costing

Clinical comparison

- comparative accuracy

- ease of use

Nursing staff perspective

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Market survey Ten vendors were identified and contacted Brands available

- 10 compact electronic- one electronic- 5 infrared tympanic- 3 infrared temporal- one Galinstan-in-glass

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Nursing Leadership Preferences Eight nurse managers questionnaire (seven multiple-choice questions + add

on)

Analysis of preferred criteria showed that the selected thermometer should display the result digitally and have the ability to measure the temperature from different sites.

ELECTRONIC or COMPACT ELECTRONIC

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Selection of the two non-mercury thermometers

Electronic

Suretemp Plus 690

(Welch Allyn – USA)

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Selection of the two non-mercury thermometers Compact Electronic

10 brands

Peak temperature alarm Fever warning

Flexible probe tip Start-up self-check

Memory function  Meet standards

MT 200 (Microlife, Switzerland)

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Comparative costing of thermometers

Types of costs included in the analysis are:

Alexander, D., & Kelly, B. (1991). Cost effectiveness of tympanic thermometry in the pediatric office setting. Clinical Pediatrics, 30(4 Suppl), 57-59.

Cost type Examples Sources of data

thermometer costs Thermometer, accessories

Vendor’s quotations

disposable supply costs

Batteries, Alcohol swabs, Probe covers

Hospital data

personnel costs Nurses' time User manual

equipment service costs

medical engineer time, Maintenance, Calibration

Personal experience

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Comparative costing of thermometers (USD)

Type of thermometers

Electronic Compact electronic

Infrared tympanic

Infrared temporal

Mercury

Total investment cost

10,029 2,719 3,292 6,580 23,092

Total annual running cost 8,807 15,603 30,543 33,556 31,213

Total cost at year one 18,836 18,322 33,835 40,136 54,305

Total cost at year ten 98,099 158,749 308,722 342,140 543,050

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Clinical evaluation: accuracyo 150 readings from five clinical departments (30 each)o Measurement sites included oral cavity (40 %), axilla

(40%), and rectum (20%) o 62% of readings were taken on female patients

Age Frequency Percentage

≤ 1 month 30 20

1 month – 18 years 32 21

19 years – 60 years 61 41

≥60 years 27 18

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Clinical evaluation: accuracy

Total sample Oral Axillary Rectal

Sample Size (readings)

150 60 60 30

Mean difference of readings (SD*)

0.45 (0.49) 0.2 (0.35) 0.775 (0.47) 0.31 (0.41)

Range of difference of readings

-0.7 to +2.2 -0.7 to +1.4 0 to +2.2 -0.4 to +1.3

95% confidence interval

0.37-0.53 0.11-0.29 0.65-0.89 0.15-0.46

t-test 11.27 4.46 12.64 4.11

P value ˂ 0.001 ˂ 0.001 ˂ 0.001 ˂ 0.001

Correlation coefficient (Pearson R)

0.64 0.7 0.65 0.81

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Clinical evaluation: accuracy

Total sample Oral Axillary Rectal

Limits of agreement [-0.534, 1.434] [-0.505, 0.905] [-0.194, 1.724] [-0.510, 1.136]

Number with 0.5°C or more difference (%)

45 (31.3) 8 (13.3) 33(55) 6(20)

Number of readings higher with compact electronic (%)

127 (84.6) 45(75) 59(98.3) 23(76.6)

Number of identical readings (%)

7 (4.6) 5 (8.3) 1(1.6) 1(3.3)

Number of lower readings (%)

16 (10.6) 10 (16.6) 0 6(20)

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Clinical evaluation: ease of use

o Ten healthcare staff (RNs & PNs) took the temperature of a volunteer three times by each thermometer.

o Such a difference translates to a 1392 $ in savings from personnel cost annually.

Comparison of the measurement time of both thermometers in seconds

Thermometer type

Mean (SD) Mean difference

Level of significance

Number of steps (range)

Electronic 21.55 (2.07)14.84 P<0.001

6 to 7Compact electronic

36.39 (4.45) 6 to 7

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Healthcare personnel perspective Five healthcare personnel (practical nurses) Five days

Question Compact electronic

ElectronicBoth are the

sameWhich thermometer is more likely to be broken during use?

- 80% 20%

Which thermometer do you think is more accurate? 20% 40% 40%

Which thermometer is easier to use? 20% 80% -

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Healthcare personnel perspective“The nylon probe covers of the MT200 are not enough

protection from nosocomial infections since micro-tears may happen to the probe cover during measurement which might affect its integrity.”

“Equipments used on isolation patients are kept in their rooms, which might increase the possibility of losing the MT200 because of its small size.”

“Removal of the probe cover of MT200 may pose a risk of contamination.”

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Healthcare personnel perspective“Adult patients were pleased more with the electronic

thermometer”

“Probes of electronic thermometer are thick causing discomfort for the neonates.”

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Recommendations

Electronic thermometers are the most cost-effective type of thermometers in the Lebanese setting.

Compact electronic thermometers cannot replace electronic thermometers from the accuracy point of view.

Electronic thermometers are easier to use than compact electronic thermometers.

Most of healthcare personnel's comments favor the electronic thermometer.

The Electronic thermometer is the recommended replacement for the mercury thermometer in Lebanon.

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Limitations The study was done in a rural governmental hospital that

may differ from other Lebanese healthcare institutions in

various ways.

the clinical evaluation of the thermometers regarding

accuracy lacked a standard reference thermometer for

comparison thereby limiting the validity of the

comparison.

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