Prothrombin Tables

Table 1. Questionnaire Respondents

Total Site Type Laboratory Classification Location

POL* Hospital IL** Waived/PPMP Moderate/High*** Accredited Urban Rural

Targeted (N) 591 333 198 60 119 247 225 324 267

Respondent (N) 297 152 117 28 45 140 112 159 138

Response rate (%) 50 46 59 47 38 57 50 49 52

*POL includes the following types of sites: physician office laboratories, clinics, community health clinics, home health agencies, health maintenance organizations, and ambulatory surgical centers.

**IL, independent laboratory.

***Moderate/High, moderate or high complexity testing, but not accredited.

Table 2. PT Test Methods

Site Type Traditional Methods POC Devices

Number Percent Number Percent

Hospital 108 61 5 7

Independent laboratory 22 13 1 1

POL 46 26 69 92

Table 3. Testing Personnel

Testing Personnel Background Sites Employing Testing Personnel With the Background

Traditional Methods POC Devices

Number Percent Number Percent

Medical technologist 171 98 34 46

Medical laboratory technician 99 57 27 36

Medical assistant 2 1 33 45

Registered nurse 3 2 23 31

On the job trained 9 5 13 18

Licensed practical nurse 0 0 12 16

Pharmacist 3 2 4 5

Phlebotomist 3 2 4 5

Laboratory assistant 3 2 2 3

Physician assistant 0 0 3 4

Advanced registered nurse practitioner 1 1 1 1

Non-registered technologist 2 1 0 0

Emergency medical technician 0 0 1 1

Table 4. PT Reagents - Traditional Methods (N=176 sites)

Reagent Manufacturer Number of Respondents Examples of Brand Names Range of ISI Values

Dade Behring 58 Innovin 0.90 to 1.13

Thromborel S

Thromboplastin C+ 1.77 to 2.21

Beckman Coulter/Instrumentation Laboratory 50 IL PT-Fibrinogen Recombinant 0.85 to 1.13

IL PT-Fibrinogen HS+

IL PT-Fibrinogen HS 1.35 to 1.44

IL PT-Fibrinogen >2.00

IL Thromboplastin

BioMerieux 24 HTF 1.15 to 1.26

Simplastin Excel 1.81 to 1.91

Diagnostica Stago 13 Neoplastin 1.26 to 1.35

Neoplastin C1+

Hemoliance 11 Recombiplastin

RTF 0.94 to 1.03

Brain thromboplastin 2.00 to 2.33

Sigma Diagnostics/Sigma Trinity Biotech 10 Thrombomax HS 1.15 to 1.31

Thromborel HS

Thrombomax 1.69 to 1.71

Pacific Hemostasis 6 None given 1.16 to 2.04

Ortho 3 None given 0.85 to 1.00

Other 1 MLA Recombiplastin 1.03

Total 176 -- 0.85 to 2.33

Table 5. Distribution of Traditional PT Reagents by ISI Values (N=172 sites)

ISI Values Number of Sites Percent of Sites

<1.20 91 53

>1.20 and <1.50 36 21

>1.50 and <1.70 3 2

>1.70 and ≤2.00 20 12

2.01 to 2.40 22 13

Table 6. PT Reagents - POC Devices (N=75 sites)

Manufacturer Examples of Brand Names Number of Respondents ISI Values

Roche Diagnostics CoaguChek 61 29 sites = 2.00

CoaguChek S 2 sites = 1.00

30 sites did not give a value

International Technidyne Corporation Hemochron Jr 8 1.00

Protime

Protime 3

Bayer Diagnostics PT-NC 5 1.00 to 1.20

RapidPoint

Thrombocard

Hemosense INRatio 1 1.00

Table 7. Specimen Acceptance and Rejection Policies

Specimen Acceptance/Rejection Issue Percent of Sites That Included the Issue in Their Written Policies Number

Properly anticoagulated specimen 98 194

Correct volume of blood 98 194

Appropriate storage temperature 97 189

Adequate labeling of specimen 96 190

Time delays prior to testing 96 187

Adequate centrifugation (speed and time) 92 178

Information on requisition and specimen label match 90 174

Adequate information on requisition 90 173

Hemolysis 90 170

Appropriate transport times 89 168

Order of multiple tubes 86 166

Lipemia 79 146

Drawing specimens from patient lines 73 136

Icterus 71 131

Collection of samples in a syringe 67 129

Difficult draws 67 127

Abnormal hematocrits 65 123

Heparinized specimens 60 113

Table 8. Evaluation of New Lots of Reagents

Quality Practice Sites That Perform

Traditional Methods POC Devices

Percent Number Percent Number

Establish patient mean of normal 95 158 35 19

Conduct parallel testing between lots 93 156 35 19

Verify reference (normal) range 92 153 62 36

Confirm calculations of INR 89 148 34 19

Verify that the ISI is correct for instrument/reagent combination 89 147 60 35

Alert clinicians when a new reagent or reagent with a different ISI is placed into use 66 107 33 19

Perform correlation studies with another method or site 42 67 40 22

Establish ISI with calibrators 20 32 30 17

Table 9. Patient Test Reports

Percent of Sites That Report Number

Test values*

PT as INR 99.6 232

PT in seconds 89 204

PT ratio 7 14

Interpretation or comments**

Reference (normal) ranges 84 211

Specimen comments 79 195

Therapeutic ranges 74 182

Interpretation 30 66

*Other responses were: patient mean of normal value (N=4), normal control value/quality control value (N=3), therapeutic range (N=1), and last dose of medication (N=1).

**Other responses were: dose of medication (N=5), clinician sees patient and knows what ranges are (N=2), extenuating circumstances (N=1), and normal patient mean (N=1).