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Table 1 Parameter values used in the model

From: Cost-utility analysis of different treatments for post-traumatic stress disorder in sexually abused children

Parameter

Value (range used in the deterministic sensitivity analysis)

Parameters used in probabilistic sensitivity analysis

Source

Clinical effectiveness for treating PTSD (and depression if present). Used in the decision tree part of the model

  

Beta distribution

 
   

α

β

 

TF-CBT only

0.42 (0.29 - 0.55)*

24.3

33.6

[15, 16, 33]**

TF-CBT + SSRI (setraline)

0.44 (0.31 - 0.57)*

23.5

29.9

 

Non-directive counselling

0.34 (0.24 - 0.44)*

27.8

54.0

 

Clinical effectiveness for treating recurrent depression (used in Markov part of the model) with SSRI

     

SSRI only (applied to treatment non-responders, and responders who relapsed into depression in the Markov part of the model)

0.6 (0.42 - 0.78)

16.5

11.0

[45, 57]

Disease pathways parameters

  

Beta distribution

 
   

α

β

 

Proportion of the cohort with co-morbid depression

0.58 (0.40 - 0.75)

  

[33]

Probability of delayed response to PTSD treatment (assumed to occur in the 6th month after treatment)

0.17 (0.12 - 0.22)

35.3

172.1

[53]

Probability of spontaneous remission from PTSD (applied to the non- treated population in the first 12 months)

0.17 (0.12 - 0.22)

35.3

172.1

[18, 53]

Probability of spontaneous recovery from PTSD over 29 years (applied to the treatment non-responders in Markov part of the model)

2 d year

0.0083

  

[53]***

 

3-4th years

0.0041

   
 

5-6th years

0.0021

   
 

7-8th year

0.0043

   
 

9-11th year

0.0035

   
 

12-13th years

0.0023

   
 

14-16th years

0.0013

   
 

17-20th years

0.0028

   
 

21-29 years

0.0020

   

Probability of spontaneous remission from depression

0.53 (0.37 - 0.69)

19.5

17.3

[45]

Probability of re-occurrence of depression in PTSD treatment responders

0.14 (0.09 - 0.18)

36.6

224.6

[33]

Mortality

0.0 (in 10-14 y.o.)

  

[37, 58]

Age-adjusted probability of suicide in general population (per 3-month cycle)

0.0000155 (in 15-19 y.o.)

   
 

0.0000316 (in 20-29 y.o.)

   
 

0.0000387 (in 30-40 y.o)

   

Age-adjusted probability of suicide in adolescents and young adults with PTSD + depression (per 3-month cycle)

0.0 (in 10-14 y.o.)

  

[37, 49, 58]

 

0.000334 (in 15-19 y.o.)

   
 

0.000343 (in 20-29 y.o.)

   
 

0.000744 (in 30-40 y.o)

   

Age-adjusted probability of suicide in adolescents and young adults with depression only (per 3-month cycle)

0.0 (in 10-14 y.o.)

  

[50]

 

0.000186 (in 15-19 y.o.)

   
 

0.000379 (in 20-29 y.o.)

   
 

0.000465 (in 30-40 y.o)

   

Age-adjusted probability of suicide in adolescents and young adults with PTSD only (per 3-month cycle)

0.0 (in 10-14 y.o.)

  

[51]

 

0.000032 (in 15-19 y.o.)

   
 

0.000066(in 20-29 y.o.)

   
 

0.000080 (in 30-40 y.o)

   

Age-adjusted probability of death from other causes except suicide in adolescents and young adults (per 3-month cycle)

0.000027 (in 10-14 y.o.)

  

[37, 58]

 

0.000070 (in 15-19 y.o.)

   
 

0.000104(in 20-29 y.o.)

   
 

0.000169 (in 30-40 y.o)

   

Mental health care resource use parameters

  

Gamma distribution

 
   

α

λ

 

One month prescription of sertraline, (100 mg)

$24.66

96.04

3.89

[56]

Cost per consultation with clinical psychologist/counsellor (MBS Australia Items 80000; 80010)

First consultation $140.90

96.04

0.68

[55]

 

Subsequent consultation $96.00

96.04

1.00

 

Cost per consultation with clinical psychiatrist (MBS Australia Items 296; 304)

First consultation $250.45

96.04

0.38

[55]

 

Subsequent consultation $125.80

96.04

0.76

 

Cost per consultation with general practitioner (monitoring and SSRI renewal if required)

$66.00

96.04

1.46

[59]

Cost of individual consultation with social worker or participation in 6 parental group sessions (Social workers schedule fee, Items SW01; SW15).

$58.85

96.04

1.63

[60]

Utility values

     
   

Gamma distribution

 

No PTSD/No depression (population norm)

  

α

λ

 

   10-30 year olds

0.87

   

   30-40 year olds

0.85

  

[53, 54]

PTSD only

0.61 (0.43 - 0.79)***

96.04

157.4

 

PTSD + depression

0.53 (0.37 - 0.69)***

96.044

181.21

 

Depression only

0.46 (0.32 - 0.60)***

96.044

208.78

 
  1. *The aggregated sample size used in direct and indirect comparison of effectiveness of active treatments vs no treatment comparator was: N = 50 in TF-CBT [16]; N = 36 in TF-CBT + sertraline [16, 33]; N = 116 in non-directive counselling [15, 16]
  2. **Clinical effectiveness (proportion of responders at the end of treatment) was adjusted for indirect comparison;
  3. ***Estimate obtained by the first author. (E. Gospodarevskaya "Prevalence of post-traumatic stress disorder, symptom duration and quality of life in sexually abused Australian children: using mental health survey data for economic analysis"; Journal of Child Sexual Abuse, 2012. Forthcoming)