Test and treat strategies for Helicobacter: RESULTS
RESULTS
Base case scenario: The number of endoscopies per 1000 patients was lowest with the CUBT strategy, higher with serology and highest with empirical ranitidine therapy (Table 3). The number of H pylori eradication regimens prescribed per 1000 patients was lowest with empirical ranitidine (200.1), highest with serology and intermediate with the ^{13}CUBT.
In the base case scenario, the direct medical cost per patient over 12 months was $598 in the ranitidine strategy, $635 in the CUBT strategy and $603 in the serology strategy (Table 3). The number of H pyloripositive peptic ulcers cured was 53/1000 patients with the ranitidine strategy, 128/1000 patients with the ^{13}CUBT and 92/1000 patients with serology. No strategy demonstrated dominance over any other because none was both more effective and less costly (Figure 2). The ratio of total cost to total number of ulcers cured was highest with ranitidine ($11,300/cure), intermediate with the serology strategy ($6,543/cure) and lowest with the ^{13}CUBT test and treat strategy ($4,945/cure).
TABLE 3 Expected oneyear outcomes, costs and incremental cost effectiveness ratios (ICER). Reported results are rounded to the nearest whole value, while calculations have been performed on unrounded values

Endoscopies 

Cost per 
Cost 
Ulcer cures 



per 
H 
patient 
increment, 
per 
Increment in 
ICER 
Strategy 
patients 
per 
(CDN$) 

patients 
cures 
((5CA5EX1000) 
Ranitidine 
700 
200 
598 
– 
53 
– 
– 
H pylori serology 
649 
449 
603 
5 
92 
39 
$118/cure 
^{13}CUBT 
629 
433 
635 
32 
128 
36 
$885/cure 
The incremental change in cost and ulcer cures was determined by advancing from the least costly and least effective strategy (ranitidine) to the most costly and most effective option (^{13}CUBT). The ICER of serology compared with ranitidine was $118 per additional ulcer cure, while that of 13 the CUBT relative to serology was $885/cure. Oneway sensitivity analysis: Each path probability and cost estimate were varied over their plausible range to determine their impact on the ICERs of ^{13}CUBT versus serology and of serology versus ranitidine. In several instances, an ICER fell below zero, implying a dominant relationship between the two alternatives. In such cases, a ‘dominance threshold’ value for that model parameter was identified as the point where the ICER numerator (cost increment) or denominator (effect increment) approached zero.
TABLE 4 Oneway sensitivity analysis examining the incremental cost effectiveness ratio (ICER) of the serology strategy versus empirical ranitidine
Model parameter 
Range 
ICER range ($/cure) 
Serology 
ICER >$1000/cure 
Serology sensitivity 
0.700.95 
47262 
N/A 
N/A 
Serology specificity 
0.700.95 
0187 
Over 0.94 
N/A 
Helicobacter pylori prevalence in dyspepsia 
0.100.50 
01400 
Over 0.35 
Below0.14 
PUD prevalence if H pyloripositive 
0.200.50 
0752 
Over 0.39 
N/A 
PUD recurrence if H pyloripositive 
0.501.00 
0282 
Over 0.88 
N/A 
PUD recurrence if H pylorinegative 
0.000.20 
65336 
N/A 
N/A 
H pylori eradication effectiveness 
0.601.00 
3492 
N/A 
N/A 
Relapse rate of NUD 
0.001.00 
45253 
N/A 
N/A 
Proportion of PUD patients with symptoms 
0.001.00 
0550 
Over 0.83 
N/A 
Cost of endoscopy 
$250$1250 
0442 
Over $610 
N/A 
Cost of serology 
$5$50 
0883 
Below $16 
N/A 
The ICER of serology versus ranitidine ranged from $0/cure to $1400/cure in sensitivity analysis (Table 4). In no circumstance did ranitidine become dominant over serology. However, serology dominated ranitidine when any of the following conditions were satisfied: prevalence of H pylori greater than 35%; prevalence of PUD greater than 39% if H pyloripositive; specificity of serology greater than 94%; proportion of ulcers with symptoms greater than 83%; annual relapse rate of H pylori–positive patients with prior PUD greater than 88%; cost of serology less than $16; or cost of endoscopy greater than $610.
Don’t blow your budget on pharmacy items now
Figure 2) Base case scenario estimates of costs and outcomes (ulcer cures per 1000 patients) for three alternative strategies. Dashed lines represent the incremental cost effectiveness ratios of successive strategies. *($603$598)/(9253) x 1000 (values rounded); +($635$603)/ (12892) x 1000 (values rounded). HP Helicobacter pylori