Diseño de los casos de prueba

The regional screening teams used their database to purposively identify a number of people with type 2 diabetes from each practice who were stratified according to age, gender, ethnicity, length of diagnosis, grade of diabetic retinopathy and that they had attended at least one diabetic retinopathy screening. Each potential participant also met all aspects of the inclusion criteria. The name of each potential participant was then passed to the

nominated gate keeper (Gallo et al., 2012) who ranged from practice

receptionists, doctors, nurses, and diabetic screeners and who contacted these individuals. The researcher arranged power point presentations to gatekeepers in order to provide information about the study, which groups the study was asking them to recruit and to answer any questions they may have. The recruitment of potential participants was therefore carried out by gatekeepers who contacted them to give an overview of the study, posted or emailed a participant information pack and explained to the individual that entry into the study was entirely voluntary and that their treatment and care would not be affected by their decision. In this way the researcher did not receive any

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participant details prior to informed consent being obtained. Potential participants who had a question about the study had the opportunity to ask the practice staff or to call the researcher on the phone number that was provided in the participant information sheet. Prior to interviews taking place, each participant sent their signed consent form to the researcher.

The use of gatekeepers to recruit participants was considered as a potential concern because their decisions about who to recruit may have been influenced by their knowledge, and interests in the study, as well as by their negotiation

skills and the daily pressures associated with a busy practice (Gallo et al., 2012;

Symonds et al., 2012). In order to ensure that this research is culturally

competent (Zeh et al., 2012; Papadopoulos, 2004; Papadopoulos, 2006), every

effort was made within time and budgetary constraints, to facilitate access for participants for whom English is not their first language. A detailed translation and interpretation protocol that details these procedures can be found in Appendix 5. The researcher had access to bilingual link workers provided by the researcher’s trust. This allowed potential people with diabetes to be contacted in an appropriate language by telephone or directly in person within the clinic to encourage recruitment of non-English speakers. Link workers were given information about the study and the practices by the researcher. Link workers liaised closely with practices to identify the relevant linguistic skills needed during recruitment. However, all people with diabetes were English speaking and chose to be interviewed in the English language. A link worker was available on two occasions as back up but was not required as participants preferred to be interviewed in the English language. Assuming a positive response rate of approximately thirty per cent, up to fifteen people with type 2 diabetes within each practice were invited to participate in the research. Thus, a total of seventy five people with type 2 diabetes were invited to participate over a two month period between September and November 2012. Within the first four weeks, fifteen consent forms were signed and returned to the researcher. Gatekeepers were asked to follow-up those individuals who did not return the consent forms by sending out another pack to all potential participants. This also ensured that gate keepers would not be able to identify those people who eventually participated in the study. A further five consent forms were signed and returned to the researcher eight weeks after the initial

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pack was sent. A total of twenty consent forms were returned to the researcher and each of these participants were contacted by telephone by the researcher to arrange an interview appointment at a time and the location of the participants’ choice. The study aimed to include equal numbers of participants according to their grade of diabetic retinopathy. This decision was made on the basis of receiving more consent forms from certain practices than others that included more people with certain grades of diabetic retinopathy, which could be due to the influence and motivation of gatekeepers during the recruitment

process (Symonds et al., 2012).

Twenty participants were recruited to this study. Participants were from different grades of diabetic retinopathy to explore the influence of diabetic retinopathy grade on perception of risk. These groups included twelve males and eight females. Of these, eleven were White British and nine were South Asians. Seven participants were females and thirteen were male. Participants were divided into four groups (Table 5.2) depending on their most recent screening outcome. Group one: seven participants (three White British and four South Asians) with no diabetic retinopathy (R0); Group two: six participants (four White British and two South Asians) who had background diabetic retinopathy (R1); Group three: four participants (one White British and three South Asians) with pre-proliferative diabetic retinopathy (R2); and Group four: three participants (thee White British and none South Asians) who had proliferative diabetic retinopathy (R3). The age of the participants ranged from forty years to eighty six years with a mean age of 62 years.

Table 5.2 Sampling Strategy for Stage One

Group Grade of diabetic retinopathy White

British

South Asians

Total

Group 1 No diabetic retinopathy (R0) 3 4 7

Group 2 Background retinopathy (R1) 4 2 6

Group 3 Preproliferative diabetic retinopathy (R2) 1 3 4

Group 4 Proliferative diabetic retinopathy (R3) 3 0 3

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