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Table 2 Parameters used in the model and their sampling distribution for the probabilistic sensitivity analysis

From: A cost-utility analysis of cervical cancer screening and human papillomavirus vaccination in the Philippines

Parameters

Mean (SE)

Distribution

Reference

Baseline Parameters

 Discount Rate for both costs and outcomes

3.5 %

 

DOH, 2013

 Age start in the model (years)

11

  

 PPP conversion factor, (Pesos per 1$)

24.8

 

World data bank, 2013

Epidemiological Parameters

 Prevalence of HPV infection

0.100 (0.064)

Beta

Myers et al. [22]

 Prevalence of CIN1

0.010 (0.010)

Beta

Myers et al. [22]

 Age specific (y) incidence of HPV infection

   

  11

0.019 (0.007)

  

  15

0.100 (0.038)

Beta

Myers et al. [22]

  16

0.100 (0.038)

Beta

  17

0.120 (0.046)

Beta

  18

0.150 (0.057)

Beta

  19

0.170 (0.065)

Beta

  20

0.150 (0.057)

Beta

  21

0.120 (0.046)

Beta

  22

0.100 (0.038)

Beta

  23

0.100 (0.038)

Beta

  24

0.050 (0.019)

Beta

  30

0.010 (0.004)

Beta

  50+

0.005 (0.002)

Beta

Yearly Transitional Probability

 HPV infection to CIN1

0.072 (0.015)

Beta

Myers et al. [22]

 CIN1 to CIN2/3 (age [y])

   

  15

0.017 (0.010)

Beta

Myers et al. [22]

  35

0.069 (0.013)

Beta

 

 CIN 2/3 to invasive CA

0.050 (0.008)

Beta

 

 Stage I to Stage II

0.438 (0.351)

Beta

Myers et al. [22]

 Stage II to Stage III

0.536 (0.351)

Beta

 

 Stage III to Stage IV

0.684 (0.140)

Beta

 

Regression

 Age-specific (y) probability of regression: HPV infection to healthy

  

Myers et al. [22]

  15

0.552 (0.084)

Beta

 

  25

0.370 (0.033)

Beta

 

  30

0.103 (0.018)

Beta

 

 Age-specific (y): CIN1 to HPV infection or healthy

  

Myers et al. [22]

  15

0.161 (0.024)

Beta

 

  35

0.082 (0.021)

Beta

 

 CIN 2/3 to CIN1 or healthy

0.069 (0.013)

Beta

Myers et al. [22]

 Proportion of CIN1 reverting to healthy

0.900 (0.128)

Beta

 

 Proportion of CIN2/3 reverting to healthy

0.500 (0.128)

Beta

 

 Proportion of having symptoms

  

Myers et al. [22]

  Stage I

0.150 (0.150)

Beta

 

  Stage II

0.225 (0.225)

Beta

 

  Stage III

0.600 (0.600)

Beta

 

  Stage IV

0.900 (0.900)

Beta

 

 Weibull survival by CA stage and patient age (y)

   

  Stage I

   

   constant

−8.749 (1.259)

Log-Normal

Praditsitthikorn et al. [17]

   Age coefficient

0.041 (0.020)

Log-Normal

   Gamma

0.589 (1.139)

Log-Normal

  Stage II

  

   constant

−7.066 (0.934)

Log-Normal

  Age coefficient

−0.014 (0.011)

Log-Normal

  Gamma

0.919 (1.120)

Log-Normal

  Stage III

  

   constant

−6.778 (0.891)

Log-Normal

   Age coefficient

0.023 (0.011)

Log-Normal

   Gamma

0.675 (1.098)

Log-Normal

  Stage IV

  

   constant

−3.863 (1.217)

Log-Normal

   Age coefficient

−0.055 (0.022)

Log-Normal

   Gamma

1.004 (1.226)

Log-Normal

Program Effectiveness Parameters

 Pap Smear

   

  Sensitivity for pre-invasive

0.552 (0.070)

Beta

Sritipsukho, [27]

  Specificity

0.915 (0.013)

Beta

 VIA

   

  Sensitivity for pre-invasive

0.716 (0.025)

Beta

Sritipsukho, [27]

  Specificity

0.793 (0.011)

Beta

 HPV Vaccine

   

  Relative risk of persistence HPV infection, 1-year

0.26 (0.064)

Beta

Rambout et al. [25]

Programme Acceptability

 Pap Smear

0.08

 

University of the Philippines-Department of Health Cervical Cancer Screening Study Group, 2001 [7]

 Proportion of Patients with CIN 2/3

   

  Receiving cryosurgery

1.000 (1.000)

Beta

Goldie et al. [44]

  Receiving cold knife conisation

0.125 (0.125)

Beta

Goldie et al. [44]

  Receiving simple hysterectomy

0.125 (0.125)

Beta

Goldie et al. [44]

  Incidence of OP visit for treating minor complications from cryosurgery

0.05 (0.05)

Beta

Goldie et al. [44]

  Incidence of IP visit for treating major complications from cryosurgery

0.01 (0.01)

Beta

Goldie et al. [44]

 Annual rate of OP visits

  

Praditsitthikorn et al. [17]

  Initial Stage

25.48 (1.41)

Gamma

  Remission Stage

7.14 (0.59)

Gamma

  Persistence Stage

38.53 (7.77)

Gamma

  Recurrence Stage

13.37 (2.02)

Gamma

 Annual rate of IP visits

  

Praditsitthikorn et al. [17]

  Initial Stage

0.77 (0.10)

Gamma

  Remission Stage

0.15(0.04)

Gamma

  Persistence Stage

0.87 (0.43)

Gamma

  Recurrence Stage

1.64 (0.31)

Gamma

Costing Parameters (in Php)

 Direct Medical Costs of Screening (per visit)

  Pap smear

965 (965)

Gamma

Primary data collected by the authors

  VIA

500 (500)

Gamma

Primary data collected by the authors

  Cost of follow up for Pap screening

500 (500)

Gamma

Primary data collected by the authors

 Cost of HPV vaccination (three doses)

2,736 (2,376)

Gamma

Price Offer to the government

 Cost of HPV booster doses

800 (800)

Gamma

Price Offer to the government

 Cost of Vaccine delivery and administration (per dose)

112 (112)

Gamma

DOH DPCB, 2013

 Unit cost of colcoscopy/ biopsy

1,120 (1,120)

Gamma

PHIC, 2013

 Unit costs

   

  Cryotherapy

1,500 (1,500)

Gamma

Primary data collected by the authors

  Loop Electrosurgical Extraction Procedure (LEEP)

12,644.54 (12,644.54)

Gamma

PHIC, 2013

  Cold knife conisation

8100.36 (8100.36)

Gamma

PHIC, 2013

  Simple hysterectomy

41,362.67 (41,362.67)

Gamma

PHIC, 2013

 Cost of hospitalization day (Php per day)

500 (500)

Gamma

Health facilities

 Hospitalization days

   

  Cold knife conisation

1

Gamma

Expert opinion

  Simple hysterectomy

5

Gamma

Expert opinion/ Primary data collected by the authors

 Medical cost of follow – up

   

  Cryosurgery

1,000 (255.10)

Gamma

Primary data collected by the authors

  LEEP/ Cold knife conisation/ Simple hysterectomy

750 (127.55)

Gamma

Primary data collected by the authors

 Unit Cost

   

  Cervical CA staging

4,485 (765.31)

Gamma

Primary data collected by the authors

  Treating complications from cryosurgery (minor)

510.08 (510.08)

Gamma

Primary data collected by the authors

  Treating complications from cryosurgery (major)

512.48 (512.48)

Gamma

Primary data collected by the authors

Annual Costs for treatment of invasive cervical CA

  Initial Stage

   

 -Stage I

77,873.00 (39,073.469)

 

PHIC 2013

 -Stage II

77,873.00

 

PHIC 2013

 -Stage III

106,390.05

 

PHIC 2013

 -Stage IV

106,390.05

 

PHIC 2013

 Remission Stage

   

 -Stage I

16,523

 

PHIC 2013

 -Stage II

16,115

 

PHIC 2013

 -Stage III

20,618

 

PHIC 2013

 -Stage IV

27,310

 

PHIC 2013

 Persistence Stage

   

 -Stage I

112,093

 

PHIC 2013

 -Stage II

93,256

 

PHIC 2013

 -Stage III

118,350

 

PHIC 2013

 -Stage IV

117,801

 

PHIC 2013

 Recurrence

   

 -Stage I

65,818

 

PHIC 2013

 -Stage II

63,747

 

PHIC 2013

 -Stage III

83,512

 

PHIC 2013

 -Stage IV

111,233

 

PHIC 2013

Utility Parameters

 Healthy Stage or CIN1-3 without complication

1.00 (1.00)

Beta

Praditsitthikorn et al. [17]

 Initial Stage

  

 -Stage I

0.74 (0.01)

Beta

 -Stage II

0.76 (0.01)

Beta

 -Stage III

0.72 (0.02)

Beta

 -Stage IV

0.63 (0.03)

Beta

 Remission Stage

  

 -Stage I

0.79 (0.01)

Beta

 -Stage II

0.79 (0.01)

Beta

 -Stage III

0.81 (0.01)

Beta

 -Stage IV

0.85 (0.05)

Beta

 Persistence Stage

  

 -Stage I

0.80 (0.20)

Beta

 -Stage II

0.80 (0.04)

Beta

 -Stage III

0.65 (0.05)

Beta

 -Stage IV

0.45 (0.05)

Beta

 Recurrence

  

 -Stage I

0.80 (0.03)

Beta

 -Stage II

0.68 (0.02)

Beta

 -Stage III

0.66 (0.04)

Beta

 -Stage IV

0.81 (0.08)

Beta

  1. DOH - Department of Health; DPCB - Disease Prevention and Control Bureau; PHIC - Philippine Health Insurance Corporation