Device Judgement Recommended

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Emma Caldwell
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1 dabl Educational Trust Validation Checklist Device Judgement Recommended Manufacturer IEM Device Stabil O Graph Category Upper Arm (Self) Mode Oscillometric Protocol Reference BHS + ESH Westhoff TH, Schmidt S, Zidek W, van der Giet M. Validation of the Stabil O Graph blood pressure self measurement device Journal of Human Hypertension 2007;22, ,Research Letter Recruitment Screened 112 (BHS), 41 (ESH) Included 85 (BHS), 33 (ESH) Excluded Explained Some Ranges Correct Yes Ages Correct Yes Sexes Correct Yes Description of Methods Good Procedure Description Good Problems Explained Results Description Good Plots Plots are absent from the letter. These were requested and are included below. Result Pass Both BHS and ESH and also on ESH subgroup from BHS sample Signoff Notes Without plots or subsections, the letter format is not an ideal method of prsenting the results but it does benefit from consiseness. Problems with a fall in pressure in the ESH study high range subjects are addressed with a confirmatory analyis using a subset from BHS study subjects. Date 14/5/2008 Plots and were requested from the authors. These and tables from the original manuscript are included below dabl Educational Trust., 34 Main Street, Blackrock, Co. Dublin

2 Tables Table 1A: Number of patients required and number of patients examined in each blood pressure group of the BHS protocol Systolic BP Diastolic BP Minimum Number of Number of (mmhg) (mmhg) number of subjects subjects subjects examined examined required (systolic) (diastolic) < 100 < >180 > Table 1B: Grading criteria of the BHS. To obtain a grade, the device must achieve percentages those reported in the table in all the three categories. Grade Percentage of readings with differences between standard and test device of 5 mmhg 10 mmhg 15 mmhg A 60% 85% 95% B 50% 75% 90% C 40% 65% 85% D Worse than C Worse than C Worse than C 17

3 Table 1C: Results of the BHS validation procedure, n=85 subjects. Numbers in column 1 correspond to number of measurement in the BHS protocol (Device measurements versus preceding and succeding Observer measurements) Mean ± SD of Grade Mean ± SD (mmhg) differences (mmhg) Observer 1 SBP (1 vs 2, 3 vs 4, 5 vs 6) DBP (1 vs 2, 3 vs 4, 5 vs 6) SBP (2 vs 3, 4 vs 5, 6 vs 7) DBP (2 vs 3, 4 vs 5, 6 vs 7) Observer 2 SBP (1 vs 2, 3 vs 4, 5 vs 6) DBP (1 vs 2, 3 vs 4, 5 vs 6) SBP (2 vs 3, 4 vs 5, 6 vs 7) DBP (2 vs 3, 4 vs 5, 6 vs 7) Final grading B 61% 88% 94% 100% ± ± 7.2 A 67% 94% 98% 100% 83.9 ± ± 5.8 A 66% 89% 96% 100% ± ± 6.6 A 67% 95% 99% 100% 83.5 ± ± 5.6 B 61% 88% 93% 100% ± ± 7.3 A 65% 94% 98% 100% 84.0 ± ± 5.8 B 66% 87% 94% 100% ± ± 6.6 A 64% 96% 99% 100% 83.5 ± ± 5.8 SBP A 66% 89% 96% 100% ± ± 6.6 DBP A 65% 94% 98% 100% 84.0 ± ±

4 Table 2A: Number of measurements required and achieved for systolic (SBP) and diastolic (DBP) blood pressure falling in specified error-categories according to phase 1 of the ESH protocol (number of subjects n=15, number of measurements n=45). Error category < 5 mmhg < 10 mmhg < 15 mmhg Required One of Achieved SBP DBP Table 2B: Number of measurements required and achieved for systolic (SBP) and diastolic (DBP) blood pressure falling in specified error-categories according to phase 2.1 of the ESH protocol (number of subjects n=33, number of measurements n=99). Error category < 5 mmhg < 10 mmhg < 15 mmhg Required Two of All of Achieved SBP DBP

5 Table 2C: Number of subjects having the ESH-specified fraction of device-observer differences 5 mmhg for systolic (SBP) and diastolic (DBP) blood pressure (number of subjects 33) Subjects with specified fraction of device-observer differences 2/3 < 5 mmhg 0/3 < 5 mmhg Required Both 22 3 Achieved SBP 25 3 DBP

6 Table 3: Number of subjects obtained for each blood pressure category according to ESH and BHS criteria in the categorization measurement (BPA) and the following validation measurements (BP1 BP7) BPA BP1 BP3 BP5 BP7 ESH Systolic mmhg mmhg mmhg Diastolic mmhg mmhg mmhg BHS Systolic <100 mmhg mmhg mmhg mmhg >180 mmhg Diastolic < 60 mmhg mmhg mmhg mmhg >110 mmhg

7 Figure legends Figure 1: Tukey mean-difference plots (BHS validation process) of systolic (A) and diastolic (B) blood pressure difference of device and observer in 85 subjects (n=255 measurements). Mean difference for systolic blood pressure is -1.9 ± 6.6 mmhg, mean difference for diastolic blood pressure is 0.1 ± 5.8 mmhg. Figure 2: Tukey mean-difference plots (ESH validation process) of systolic (A) and diastolic (B) blood pressure difference of device and observer in 33 subjects (n=99 measurements). Mean device-observer differences were 0.0 ± 5.6 mmhg (systolic) and 1.0 ± 5.7 mmhg (diastolic). 24

8 Figures Figure 1A 25

9 Figure 1B 26

10 Figure 2 Figure 2A Figure 2B 27

Validation Study Result Form

Validation Study Result Form Please complete Section 1 to Section 5 of this form and return it to dabl Educational Trust with copies of the validation Study Ref. plots. In Section 3 to Section 5, complete