MEDIDAS CAUTELARES EN EL CODIGO PROCESAL PENAL

The target population included pharmacy managers of all community pharmacies within the North Thames (East) Region. The decision to conduct the research within this Region was based on a number of considerations:

1) In 1992 there were 900 community pharmacies within the North Thames (East) Region and resources were available to survey a population of this size. It was necessary to survey a population of several hundred pharmacists, in order to identify sub-groups who were providing diagnostic testing on the pharmacy premises.

2) The decision to conduct a detailed survey, during phase 2, in one Regional Health Authority (RHA) rather than to sample fiom a larger target population, for example by conducting a National Survey, was based on response rate and follow-up considerations. It has been suggested that a survey local to the School of Pharmacy finom which the research was conducted, may achieve higher response rates than a survey posted to a remote part of the country. From a practical viewpoint, follow-up and observational validation studies are more practicable and less expensive if the target population is local to the researcher.

3) Of the 14 Health Authority Regions existing at the time, the North Thames (East) Region reported the second highest number of AIDS cases, and any HTV-prevention initiatives, including pharmacy-based ones, are particularly relevant to this region.

4) The Region spans geographical areas from inner London to rural Essex, thus providing opportunity to compare urban, suburban and rural pharmacy-based health promotion.

2.2.4. Choice of Sampling Frame.

The sampling frame defines the study population and any differences between the target population and the sampling frame give rise to non-sampling bias (Henry, 1990). In order to exclude non-sampling bias, the FHSA lists of community pharmacy premises were used as a sampling frame. The RPSGB Register of Premises was not used as a sanq)ling frame, since this list is arranged by county and post town, and would have given rise to problems in identifying pharmacies in the target population when Health Authority boundaries did not coincide with county boundaries.

2.2.5. Selection of Main Study Sample. 2.2.5.1 Selection of Sample Size.

In exploratory research, the aim is to interview a small sample that is typical of the respondents from whom data will be collected in the main survey (Oppenheim, 1992). Whilst it is actually impossible to sample respondents of every kind, efforts to ensure a good spread of respondent characteristics, will enhance the breadth of data. However, the quality of exploratory interviews is much more in^ortant than the quantity of interviews (Oppenheim, 1992).

The typical number of "in-depth interviews" is 30 or 40 (Oppenheim, 1992). In order to elicit the salient outcomes and salient referents, needed for testing the TRA, Rshbein and Ajzen (1980) recommend conducting approximately 50 interviews. Considerations about resources of time and cost also influenced the number of interviews that were conducted. The initial aim was to conduct 50 interviews within a period of 4 months, but to consider whether more information was actually being gathered as the number of interviews increased. If at any stage the researcher was aware that no new issues were arising, no further interviews were to be arranged. When such a stage is reached it is not worthwhile continuing to interview new people, and the researcher's time is best spent analysing the data (Oppenheim, 1992).

2.2.5.2 Choice of Sampling Method.

The method of sampling was chosen after consideration of the sampling frame available, the resources for data collection, and the intended use of the findings. The methods available for selecting 50 pharmacies from the total number of community pharmacies in the North Thames (East) Region included non-probability and probability sampling techniques.

Non-probability techniques of sampling should only be used when probability sampling is impossible, too expensive or too time consuming, because subjective judgements are used to select respondents (Henry, 1990). In this study probability sampling was used

because it enhances the external validity and credibility of the findings. Although sample results were not used to infer results for the entire community pharmacy population of North Thames (East) Region, random sampling was used in an attempt to select an unbiased sample of pharmacists i.e. to ensure that each pharmacy in the Region had an equal chance of selection.

Proportionate random stratified san^ling was chosen to ensure representation of community pharmacists from each FHSA within the North Thames (East) Region. The technique involved dividing members of the survey population into groups or strata and then taking random samples within each stratum (Henry, 1990; Harding et al 1990). Proportionate stratification uses the same sampling fraction in each strata, and although it ensures representation of strata, costs of travel and time can be extensive if fieldwork is involved (Henry, 1990). The costs of interviewing pharmacists selected from a random stratified sample within the Region were weighed up against the risks of loss of geographical representation which would have occurred if non-stratified sampling had been employed. Proportionate probability sampling decreases sanç)ling variability and is advantageous in that responses do not have to be weighted during quantitative analysis, as is the case with disproportional stratification (Henry, 1990). The sampling frame and the resources available enabled selection of a random stratified sample of 50 community pharmacies in the North Thames (East) Region, stratified by FHSA.

2.2.5.3 Method of Sampling.

The 50 pharmacies were selected by proportionate random stratified sampling. Each pharmacy address, present on the FHSA lists was assigned a unique reference number. The sampling fraction, f, was calculated by dividing the desired sanq)le size (50) by the size of the study population (9(X)). The sampling fi-action was multiplied by the total number of pharmacies in each FHSA (t), in order to determine the total number of pharmacies that would be required to participate in each FHSA (f x t). This number was then doubled to allow for a participation rate slightly lower than that achieved during the pilot study.

A random start in a table of random numbers was selected. For Barking and Havering FHSA, the first 8 random numbers corresponding to reference numbers within the FHSA, were selected. This procedure was repeated for the other 5 FHSAs and a total of 1(X) reference numbers were chosen. The pharmacies were contacted in order of selection from the random number tables, and only if a pharmacy manager refused to participate in an interview was the next pharmacist contacted. Therefore it was not necessary to contact all 100 pharmacies and a final response rate of 63.3% was achieved.

2J2.6 Participation Rates.

The participation rates for pharmacists in each FHSA arc shown in Table 2.1. Table 2.1: Participation rates for pharmacists in semi-structured interviews.

FHSA Total number of pharmacists:

Participation rate % contacted interviewed refused

Baildngand Havering 6 4 2 6 6 . 7 Camden and Islington 14 7 7 5 0 . 0

City and East London 16 10 6 6 2 . 5 Enfield and Haifagay 13 7 6 5 3 . 9 Essex 24 16 8 6 6 . 7 Redbridge and Waltham Forest 6 6 0 1 0 0 . 0 Total 79 50 28 6 3 . 3

2.2.6.1 Reasons for Non-participation in Interviews.

Table 2.2 shows the reasons for non-participation stated by community pharmacists and the numbers of pharmacists giving each reason.

Table 2.2: Reasons reported by pharmacists for non-participation in interviews. Reason stated for non-participation Number of pharmacists

Pharmacist unable to spare 45 minutes/ too busy

15

Staffing problems 5

Pharmacy being run by locums 4

Pharmacist away on holiday or going on holiday in the next few weeks

3

Conflict with company policy 2

Pharmacist going away on maternity leave 1

Pharmacy too small for 3 people at one time 1 2.2.7 Choice of Location for Data Collection.

The choice of location and timing for data collection was based on considerations of participation rates and reliability of data. It was assumed that pharmacists would be reluctant to participate in interviews outside the opening hours of the pharmacy. Pilot studies revealed that it was feasible to conduct interviews on the pharmacy premises during opening hours, and acceptable participation rates were achieved. For face-to-face

interviews Oppenheim (1992) recommends that environments which may make the respondent feel intimidated, uncomfortable, uneasy, or threatened in be avoided and conducting interviews on the pharmacy premises had the added advantage of helping to make the interviewee feel relaxed.

Respondents are inclined to exaggerate, or make understatements in order to give the researcher the information they think he/she wants to hear and the researcher should take steps to minimise such inaccuracies (Moser and Kalton, 1971). The responding pharmacists may have experienced a social pressure to be seen to be providing health promotion services, or be heard to support the "extended role", when in fact they did not In an attempt to enhance the reliability of the data, interviews were conducted in the pharmacy, where the respondent would be aware that the researcher could see for herself which health promotion services were being provided.