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Table 1 Input parameters for the decision tree and the Markov model on clinical effectiveness

From: Image-guided navigation for locally advanced primary and locally recurrent rectal cancer: evaluation of its early cost-effectiveness

The observed number of patients

LARC

LRRC

Source

Having a negative surgical margin (R0)

 After navigated surgery

13 (n = 14)

15 (n = 19)

[A]

 After standard surgery

85 (n = 101)

20 (n = 41)

[B]

Having progression per year

 after R0 1st year

29 (n = 85)

9 (n = 20)c

[B]

 after R0 2nd (for LRRC: and 3rd) year

9 (n = 85)

4 (n = 20)c

[B]

 after R0 3rd yeara

4a(n = 85)

–

[B]

 after R1 1st year

11 (n = 16)

11 (n = 20)

[B]

 after R1 2nd and 3rd year

1 (n = 16)

3 (n = 20)

[B]

Died due to CRC after progression; over a timeframe of 3 years

 after progression in the 1st year

25 (n = 41)d

13 (n = 20)

[B]

 after progression in the 2nd and 3rd year

2 (n = 13)d

3 (n = 7)

[B]

Parameters used in the decision model

LARC

LRRC

Distribution

Source

Mean

SE

Mean

SE

Negative surgical margin rate (R0)

 Navigated surgery

0.93

0.0665

0.79

0.0911

Beta

[A]

 Standard surgery

0.84

0.0362

0.49

0.0771

Beta

[B]

Transition probability for Disease-free to Progression after a negative surgical margin (R0)

 from DF to PD in the 1st year

0.103

0.0328

0.159

0.0798

Beta

[B]

 from DF to PD in the 2nd year

0.047

0.0229

0.100

0.0656

Beta

[B]

 from DF to PD in the 3rd year

0.013

0.0121

0.100b

0.0656

Beta

[B]

Transition probability for Disease-free to Progression after a positive surgical margin (R1)

 from DF to PD in the 1st year

0.252

0.105

0.252

0.0926

Beta

[B]

 from DF to PD in the 2nd year

0.0275

0.0397

0.159

0.0780

Beta

[B]

 from DF to PD in the 3rd year

0.0275b

0.0397

0.159b

0.0780

Beta

[B]

Transition probability for Progressive Disease to Death

 from PD in the 1st year to Death

0.090

0.0665

0.135

0.0745

Beta

[B]

 from PD in the 2nd and 3rd year to Death

0.030

0.0362

0.089

0.1007

Beta

[B]

Transition probability for Disease-free to Death

0.0028

–

0.0044

–

–

[20] background mortality

  1. SE Standard error, DF Disease Free, PD progression of disease, CRC ColoRectal Cancer; [A] Prospective data collection within the navigated group at the NKI-AVL [12]; [B] Retrospective data collection within the control group at the NKI-AVL [12]
  2. aOnly in the LARC group, among patients showing a negative surgical margin enough events were found in both the 2nd and 3rd year to calculate probabilities for both years. In the other groups, we found limited events and decided to calculate a combined probability for the 2nd and 3rd year
  3. bshows the transitions that were similar for the 2nd and 3rd years. This probability was based on the sum of events occurring in the 2nd and 3rd years
  4. c1 of the LRRC patients received two surgeries and were both included in the analysis by Kok et al. For evaluating progression of disease this does not make sense, therefore this patient was excluded. Therefore the sum is 40 instead of 41
  5. dThe total number of patients having progression in the 1st, and 2nd and 3rd year is different from the number presented between brackets in the lines for died due to progression. After R1 in the 1st year, all 12 events occurred in the 1st year and none in the 2nd and 3rd year. To incorporate uncertainty surrounding the chance on having progression in the 2nd and 3rd year we moved 1 event to the second year to calculate the transitions from disease-free to progression. Therefore, the number of patients progressed in the row for patients died due to progression shows one person more for the 1st year, and one person less for the 2nd and 3rd year
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BMC Cancer

ISSN: 1471-2407

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