PhD: Broadening the valuation space in health technology assessment: the case of monitoring individuals with ocular hypertension

The economic evaluation (EE) component of health technology assessments (HTA) often defines value in terms of health related quality of life, with many HTA agencies requiring the use of EQ-5D based quality adjusted life years (QALYs). These approaches do not capture value derived from patient experience factors and the process of care. This thesis widened the valuation space beyond this limited perspective, taking account of such factors, using monetary values generated from a DCE, incorporating these into a discrete event simulation (DES) and conducting a cost–benefit analysis (CBA).

The case study monitored individuals with ocular hypertension (Project Number B2.21). Five strategies were compared using a DES: (1) ‘treat all’ at ocular hypertension diagnosis with minimal follow-up; (2), (3) biennial monitoring (either in primary or secondary care) with treatment according to predicted glaucoma risk; and monitoring and treatment according to the UK National glaucoma guidance (either (4) conservative or (5) intensive).

Outcome and Translation

DCE based WTP estimates for health outcomes (e.g. risk of developing or progressing glaucoma and treatment side-effects), patient experience factors (e.g. communication and understanding with the healthcare professional) and process of care (e.g. monitoring setting) were obtained. Conditional logit, mixed logit preference space and mixed logit WTP-space (rarely used within health economics) econometric specifications were used. These WTP valuations were aggregated in the DES, as fixed mean values or allowing variation between simulated individuals.

While the standard cost–utility analysis (CUA) using EQ-5D implied that ‘treat all’ was most likely cost-effective, CBA with broadened valuation space identified, consistently across different econometric specifications, ‘biennial hospital’ as the best choice.

This thesis proposed an approach to broaden the valuation space that can be promptly used for EE-HTA. Researchers should be attentive of the valuation space considered in their EE and choose wisely the EE approach to be used (e.g. CUA and/or CBA).

PhD student: Rodolfo Hernández

Supervisors: Mandy Ryan (HERU), Jen Burr (St Andrews University) and Luke Vale (Newcastle University)


Burr, J.M., Botello-Pinzon, P., Takwoingi, Y., Hernandez, R., Vazquez-Montes, M., Elders, A., Asaoka, R., Banister, K., van der Schoot, J., Fraser, C., King, A., Lemij, H., Sanders, R., Vernon, S., Tuulonen, A., Kotecha, A., Glasziou, P., Garway-Heath, D., Crabb, D., Vale, L., Azuara-Blanco, A., Perera, R., Ryan, M., Deeks, J. and Cook, J. (2012) 'Surveillance for ocular hypertension: an evidence synthesis and economic evaluation', Health Technology Assessment, 16(29).

Hernández, R. (2016) 'Broadening the valuation space in health technology assessment: the case of monitoring individuals with ocular hypertension', PhD Thesis, HERU, University of Aberdeen.

Hernández, R., Burr, J.M., Vale, L., Azuara-Blanco, A., Cook, J.A., Banister, K., Tuulonen, A. and Ryan, M. (2016) ‘Monitoring ocular hypertension, how much and how often? A cost-effectiveness perspective,’ British Journal of Ophthalmology, 100, 1263-1268.


Hernández, R., Ryan, M., Vale, L., Botello Pinzon, A., Burr, J. (2012) 'Incorporating discrete choice experiments into an economic evaluation: a case study of preferences for alternative monitoring services for individuals with ocular hypertension', Health Economists Study Group Meeting, Oxford, 25-27 June 2012.

Hernández, R., Vale, L., Ryan, M. and Burr, J. M. (2014) 'Incorporating results from a discrete choice experiment into a discrete event simulation model', 1st Meeting of the International Academy of Health Preference Research, Amsterdam, 8 November 2014.

Hernández, R. (2016) 'Broadening the valuation space in health technology assessment: the case of monitoring individuals with ocular hypertension', Health Economics Group Seminar, Newcastle University, Newcastle, England, 30 June 2016.