Ponderación de los parámetros y factores de las dimensiones

The findings of both literature reviews, along with other key data sources including clinical guidelines and test performance data, were mapped to the key stages in the STI testing and treatment pathway shown in figure 2.1. In considering the inclusion of potential attributes in this list the following selection criteria were used. Attributes were included in the list of potential attributes if they were:

• From the stated preference studies literature review, directly related to the provision of testing and treatment services for STIs in England

• From the broader preference literature review directly related to the provision of testing and treatment services for STIs in England

• Could be inferred from the studies considering values, beliefs, perceptions e.g. stigma associated with testing for STIs. Location of testing and how you access a healthcare professional may impact on stigma associated with attending sexual health service clinic venues.

The attribute long list, along with preliminary definitions, is set out in table 4.12:

Potential Attribute Preliminary Definition

Sample Collection Method How your sample is provided e.g. self-sample,

you see a healthcare professional and they take the sample for you

Range of STIs Tested for Which STIs you get tested for e.g. one STI, some

STIs, most STIs, all STIs, specific named STIs

Where you do the Test Where you do your test e.g. self-test at home,

self-sample at home and send off for analysis, attend GP practice, community service, sexual health service

Time to Result How long it takes from providing the sample to

getting the result e.g. 15 mins, 1 hour, 2 hours, 24 hours, 7 days, 14 days

Test Accuracy How accurate the test result is e.g. could be

defined as sensitivity, specificity, false positive, false negative etc.

Results Notification How you get your results e.g. text, email, phone

call, internet etc. Access to a Health Care

Professional when you get your result

Whether you have access to a healthcare

professional for advice when you get your result. Treatment Consultation

Method How you have your consultation for treatment e.g. online consultation, phone consultation, video consultation, face-to-face

Where you go to get

treatment If you need to see a healthcare professional in person for treatment where you go e.g. GP, sexual health clinic

Partner Notification

Method How you notify your partner of your diagnosis e.g. in person, by phone, by text, partner notified by a service provider

Type of Health Care

Professional The type of healthcare professional delivering your care e.g. Pharmacist, GP, nurse, sexual health consultant

Knowledge of Health Care

Professional Whether the health care professional has specialist knowledge of STIs

The ‘long list’ of potential attributes identified in table 4.12 was taken forward into focus groups with young people as described in the next chapter.

4.4

Summary

Bridges and colleagues identify the need to ensure the use of an evidence base on the “potential range of preferences and values that people may hold” (Bridges et al., 2011:405). They suggest literature review, other evidence on the impact of disease or health technology being assessed, expert opinion, qualitative research and other preliminary studies as the primary sources for attribute identification. The value of the qualitative research process in DCE questionnaire design is summarised by KlØjgaard and colleagues who recognised that their phased approach to qualitative research (incorporating a number of qualitative techniques) in attribute and level selection and questionnaire design had a direct impact on the final questionnaire as understanding and insight would have been missed had the qualitative methods been restricted to one approach (Kløjgaard et al., 2012).

Whilst the importance of qualitative research in DCE questionnaire design is recognised, there is little guidance on how the research undertaken should be applied in the final selection of attributes and levels (Coast and Horrocks, 2007). The ISPOR good practice checklist for conjoint analysis highlighted qualitative research as being a good practice for the selection of attributes, alongside clinical experts and other studies, for both the selection of attributes and potential attribute levels (Bridges et al., 2011).

The publication of information regarding the selection of attributes and levels is problematic with little or no information being published as part of the reporting of a DCE (ibid). A recent review of DCE studies in health economics found a decrease in the use of qualitative methods for attributes selection in studies published during 2001-2008 (69%) to 51% in studies published between 2009 and 2012.

Conversely the use of qualitative methods to inform level selection increased between the two periods from 33% for studies published during 2001-2008 to 40% for studies published between 2009 and 2012 (Clark et al., 2014). This makes it difficult for the reader to consider the implications of the selection of attributes and levels on the interpretation and limitations of the DCE study (Coast and Horrocks, 2007). The question remains as to the degree to which DCEs are sensitive to the process used to develop attributes (Coast et al., 2012).

A key question in the selection of attributes is the balance between what is important in the context of the policy/ service perspective and the perspective of the respondent (Bridges et al., 2011, Lancsar and Louviere, 2008). It is suggested that “the eventual balance of these competing objectives must be guided by the research question and the study perspective” (Bridges et al., 2011:405). It is recognised that it is not always possible to include all relevant attributes and levels within the DCE and Lancsar and Louviere suggest that DCEs need to both capture sufficient relevant attributes to avoid respondents making assumptions regarding missing attributes of importance and that levels are sufficiently different to avoid respondents discounting attributes because of little difference (Lancsar and Louviere, 2008).

Bridges and colleagues suggest that the approach to mitigate this is that “attributes central to the research question or to the decision context must either be included or held constant across all profiles.” (Bridges et al., 2011:405).

Having undertaken two literature reviews to inform the identification of the ‘long list’ of attributes, Chapter 5 outlines the qualitative work undertaken to inform the final selection of attributes and levels to be used in the DCE. This includes the use of focus groups to seek the views of young people on the ‘long list’, and exploring the findings of these with expert groups to incorporate the policy and service perspective to inform a final selection of sensible attributes and levels using an evidence synthesis process.

5

CHAPTER 5 – SELECTING THE ATTRIBUTES & LEVELS –

FINDINGS FROM THE FOCUS GROUPS AND EXPERT

GROUPS

5.1

Introduction

This chapter builds on the information presented in Chapter 3 which outlines the rationale for the use of focus groups to inform the development of the DCE, presenting the research undertaken to inform the selection of attributes from the ‘long list’ identified in Chapter 4, and identification of levels through the use of focus groups, expert groups and evidence synthesis. This chapter is structured into four parts: first, the focus group research undertaken with young people is presented. This includes the detail of the methods used, how the focus groups were conducted and analysed and the findings from this research. Second, the findings from the focus groups are used to inform the development of the expert groups which follow in this chapter. Third, the synthesis of the findings from the focus groups and expert groups to finalise the selection of attributes and levels is presented. Finally, the chapter concludes with a summary of the attributes and levels selected to move forward into the DCE presented in Chapter 6.