Health state utility valuation in radioactive iodine-refractory differentiated thyroid cancer

Figures & data

Table 1 Participant sociodemographics and EQ-5D-3L responses

	Participants (n=100)		UK census (Office of National Statistics, 2011)
Sex (male), n	45		49%
Mean age, years (SD)	41.9 (15.9)		38.2
Ethnic background
White	92		92.1%
Mixed race	2		1.9%
Asian/Asian British	3		4.0%
Chinese	3		Not captured
Main activity
Employed	65		73%
Student	18		5.2%
Retired	9		3%
Stay at home	6		5.2%
Qualifications
Completed university	47		27%
Left school at 18 with qualifications or technical/vocation qualification	29		16%
Left school at 16 with qualifications or no formal qualification	15		51%
Other	9		6%
Relationship status
Single	25		36%
Partnership	10		–
Married	59		48%
Divorced/separated	4		10%
Widowed	2		5%
EQ-5D-3L responses	Moderate (%)	Extreme (%)	Moderate (%)	Extreme (%)
Mobility	9	0	18.3	0.1
Self-care	0	0	4.1	0.1
Usual activities	7	1	14.2	2.1
Pain/discomfort	18	1	29.2	3.8
Anxiety/depression	9	1	19.1	1.8

Abbreviation: SD, standard deviation.

Table 2 Mean observed utilities for RR-DTChealth states and Incremental impact of health states on utilities compared to a base state of stable/no response with no adverse events

Parameter	Observed mean utilitya		Unadjustedb		Adjustedc
	Mean utility (standard deviation)	95% confidence interval	Utility value	95% confidence interval	Utility value	95% confidence interval
Base state – stable/no	0.80 (0.19)	0.77, 0.84	0.86	0.83, 0.90	0.87	0.84, 0.91
response
Response to therapy	0.86 (0.15)	0.83, 0.89	+0.04	0.01, 0.07	+0.04	0.01, 0.07
Progressive disease	0.50 (0.28)	0.45, 0.56	−0.37	−0.43, −0.31	−0.35	−0.41, −0.29
Diarrhea	0.42 (0.29)	0.36, 0.48	−0.48	−0.54, −0.43	−0.47	−0.52, −0.41
Fatigue	0.72 (0.24)	0.67, 0.77	−0.08	−0.13, −0.04	−0.08	−0.12, 0.04
Hand and foot syndrome	0.52 (0.30)	0.46, 0.58	−0.35	−0.42, −0.29	−0.34	−0.40, 0.28
Alopecia	0.75 (0.21)	0.71, 0.79	−0.05	−0.09, −0.01	−0.05	−0.08, 0.01

Notes:

a Mean observed TTO health state utilities.

b Derived from reduced parameter model (health states only).

c Adjusted for educational qualification level and EQ-5D-3L (usual activities and anxiety/depression) ratings using UK norms.

Abbreviations: RR-DTC, radioactive iodine-refractory differentiated thyroid cancer; TTO, time trade off.

Table 3 Parameter estimates of time trade-off utilities (mixed effects model) including statistically significant health states and sample variables in the overall multivariable model

Parameter	Parameter estimate	Standard error	P-value	95% confidence intervals
Intercept	1.548	0.177	0.000	1.2, 1.9
Treatment response health states
Stable/no response
Response (partial/complete)	0.406	0.139	0.004	0.13, 0.68
Progressive disease	−1.845	0.139	0.000	−2.12, −1.57
Stable treatment response + AE health states
AE: diarrhea	−2.325	0.139	0.000	−2.6, −2.05
AE: fatigue	−0.576	0.139	0.000	−0.85, −0.30
AE: HFS	−1.793	0.139	0.000	−2.07, −1.52
AE: alopecia	−0.356	0.139	0.011	−0.63, −0.08
EQ-5D-3L
EQ-5D: any usual activity problems	−0.871	0.403	0.031	−1.66, −0.08
EQ-5D: any anxiety/depression problems	1.238	0.465	0.008	0.33, 2.15
Qualifications
Left school at 18 with qualifications or technical/vocational qualifications	0.470	0.254	0.064	−0.33, 0.97
Left school at 16 with qualifications or no formal qualifications	0.861	0.335	0.010	0.20, 1.52

Abbreviations: AE, adverse event; HFS, hand and foot syndrome.