Healthcare Quarterly Vol.16 No.1 2013 83 82 Healthcare Quarterly Vol.16 No.1 2013

$32.2

1-Conventionalcytology (CC)

2 - LBCThinPrep

3 - LBCSurePath

4 - LBC forprimary

testing & HPVtriage

5 - HPV forprimary

testing & LBC

6 - HPV forprimary

testing & LBCimplementover 5 yrs

7 - HPV forprimary

testing & CC

8 - HPV forprimary

testing & CCimplementover 5 yrs

Tota

l Dis

coun

ted

Cost

s (in

Mill

ions

of D

olla

rs)

50

45

40

35

30

25

20

15

10

5

0

$42.2$43.4

$21.6

$26.5

$17.6$20.1

5-yeardiscountedcosts -$millions

$40.6

FIGURE 1. Total discounted costs over five years*

HPV = human papillomavirus; LBC = liquid-based cytology.

*3% discount rate

Cost

per

Spe

cim

en (i

n D

olla

rs)

1 - Conventionalcytology (CC)

2 - LBC, ThinPrep 3 - LBC, SurePath 4 - LBC for primarytesting & HPV

triage

5 - HPV primarytesting & LBC

6 - HPV for primarytesting & LBC;

implementover 5yrs

7 - HPV for primarytesting & CC

8 - HPV for primarytesting & CC;

implementover 5yrs

50

45

40

35

30

25

20

15

10

5

0

$34.0$37.4

$38.2

$45.7

$40.1

$45.6

$39.8

$30.1

$35.8$37.9

$33.8

$27.7$26.2

$28.0 $28.0

$47.4Cost per specimen in Year 1 Cost per specimen in Year 5

FIGURE 2. Summary of estimated cost per specimen in year one versus year five

HPV = human papillomavirus; LBC = liquid-based cytology.

Comparative Models of Cervical Cancer Screening in Manitoba Linda DeRiviere et al. Linda DeRiviere et al. Comparative Models of Cervical Cancer Screening in Manitoba

• Improvedqualityassuranceproceduresinlaboratories• Reducedlabourcosts,whichisdesirable• Improved cancer rates,which reducemarginal costs of

hospitalization treatment• Reducedrateofunsatisfactoryspecimensandrepeatcytology

The following are eight proposed models (the details of each model are listed in (Appendix A at http://www.longwoods.com/content/23238):

• Modelone:conventionalcytology• Modeltwo:LBCusingtheThinPreptechnology• Modelthree:LBCusingSurePathtechnology• Modelfour:LBCforprimaryscreening,triagedwith

HPV testing • Modelfive:HPVDNAasprimaryscreeningandLBCfortriage

of HPV-positive women aged 30 years or older, as well as LBC cytology as primary screening for women under age 30, both implemented in year one

• Modelsix:sameasmodelfive,butwithafive-yeargradualimple-mentation of HPV DNA testing as primary screening

• Model seven:HPVDNAtesting asprimary screening andconventional cytology for triage of HPV-positive women aged 30 years or older, and implemented in year one

• Modeleight:sameasmodelseven,butwithafive-yeargradualimplementation of HPV DNA testing as primary screening

Results Figures 1–5 show the key findings of the cervical screening study. Figure 1 shows the net present value of total costs for the eight models over the five-year period using a 3% discount rate, which is recommended in the Health Canada literature (Health Canada 2004). The models were estimated using 5% and 8% discount rates, and the ordering of absolute costs in Figure 1 did not change (data not shown).

As shown in Figure 1, HPV DNA testing as a primary screening model was the least-cost technology platform when all incremental direct healthcare costs were considered. HPV DNA triaging with conventional cytology was the least costly model of service delivery (models seven and eight). The second-place lower-cost option was HPV DNA triaging with LBC (models five and six). However, the reduced costs in the HPV screening models were contingent on significant labour reductions at project initiation, either immediately (models five and seven) or gradually over a five-year period (models six and eight).

LBC as primary screening was the least labour-saving technology platform (models two to four). Labour requirements were only slightly higher than the baseline model, even though reduced slide preparation and evaluation times were expected. However, irrespective of whether the ThinPrep (model two) or SurePath (model three) platforms were used, capital costs and consumables, such as collection supplies, increased substan-tially. The major shortcoming of LBC models was that they

were at least twice as costly as the lowest-cost HPV DNA model (seven). Though model four triaged LBC with HPV testing, it was the most expensive technology platform since labour reduc-tions were not anticipated and HPV screening was adopted on a much smaller-scale compared with the variants of models five to eight. Hence, LBC increased the cost of cervical cancer screening substantially.

Figure 2 summarizes the average total cost per specimen for each model in year one compared with year five. While costs increased in models one to four due to rising labour costs, the cost per specimen decreased in the models of HPV DNA as primary screening. The challenge of model five, HPV DNA as the primary screening test and LBC for some women, was that the total number of specimens fluctuated each year (205,000 in years one and four; 95,000 in years two, three and five). However, labour and other fixed costs were relatively constant. In particular, labour was not assumed to be flexible to changing quantities of tests over this period. This affected the cost per unit since fixed costs of labour were spread over fewer specimens in year five compared with year one. The fluctuating quantities of specimens each year also affected the estimates per specimen in model seven, HPV DNA as primary screening with conven-tional cytology, but to a lesser extent compared with model five, which had additional costs associated with the LBC platform.

Figure 3 shows the percentage change in cost per specimen from year one to year five, as was based on two calculations. First, we calculated the percentage change in annual cost per specimen, which excluded capital purchases of equipment, such as micro-scopes in the conventional cytology model and processors in the LBC model. All other costs and savings to the healthcare system were included in the estimate.

In a second calculation, we estimated the laboratory cost per specimen, which included labour costs (e.g., technologists, cytopathologists and laboratory assistants), as well as consum-ables, such as LBC and Qiagen’s Hybrid Capture 2 (hc2) tests. Colposcopy costs, physician tariffs and savings to the healthcare system were excluded from this estimate, as well as capital costs. As shown in Figure 3, the cost per specimen in the conventional cytology model increased steadily by 10–13% over the five-year period. Similarly, the models that adopted LBC without HPV testing as the primary screening platform (models two to four) incurred significant cost increases per specimen from year one to year five (models two and four: 19–24%; model three: 14–15%). The increases were attributed primarily to rising labour costs since the number of cervical screening specimens did not vary each year. The SurePath technology in model three was more capital intensive and, therefore, the marginal costs did not rise as quickly as the other models based on LBC (models two and four). As