Methodological consideration .1 Selection of research method

When weighing up which research design to use, the considerations were the nature of the research questions, the objectives of the study and the practicalities of the study setting.

The aim of this study is to assess the effect of the CBCLBP programme on HLOC and other co-variables in patients with NSCLBP before, during and after programme. Research designs that are often used to evaluate the effect of intervention in clinical settings include before and after studies, comparative trials and RCTs (Hicks, 2009). RCTs are widely regarded as the gold standard design to study the effect of an intervention in the research community.

However, there were several reasons why RCT design was not chosen for the present study. First, the CBCLBP programme is a recommended second-line treatment in accordance with local departmental policy and evidence-based guidelines for NSCLBP (Savigny et al., 2009; Chou et al., 2009; Koes et al., 2010). Since this is already an existing second-line treatment for this subgroup of NSCLBP following an initial contact and individual treatment with physiotherapists. There is no other form of second-line physiotherapy care can be randomised into. Second, the main intention of this study is to determine the effect of the CBCLBP programme over time. Therefore, a chosen method should allow meaningful comparison between treatment and no treatment phase by repeated assessment over the study period, instead of between treatment and no treatment group. Third, there are practical issues. RCTs are often difficult to conduct in terms of cost, time, manpower and resources. Besides, RCTs often involve a large number of patients, which is particularly challenging for a single-handed researcher like the PI who works in a busy NHS setting with limited allocated resources and time. Lastly, it can be ethically problematic because once patients are referred into the physiotherapy service, having “no treatment” control group is considered as unethical.

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3.3.2 Same-subject design

Alternatively, a same-subject design is a practical and useful evaluation method for applied research to assess effectiveness of an intervention on same group of subjects (Kratochwill & Levin, 2015). This methodology is often utilised by researchers in rehabilitation and social sciences to test the efficacy of an intervention on a particular problem (Backman et al., 1997; Horner et al., 2005). It is used in many fields by various professional groups such as applied behaviour analysts, clinical psychologists, social workers (Kratochwill &

Levin, 2015), and cognitive-behaviour therapists (Engel & Schutt, 2012).

One of the most unique features of same-subject design is that the baseline data of this same group of people serves as its own control, thus error variance is reduced. Besides, this method is ethically safe, because all participants received treatment and treatment did not have to be withdrawn. In addition, it allowed the PI to observe the effect of the CBCLBP programme before, during and after the programme. Therefore, the single-subject design method is considered to be an appropriate design for the current study for both conceptual and practical reasons.

3.3.3 Comparing different types of same-subject designs

There are various types in the same-subject design, such as A-B, A-B-A, and A-B-A-B design (Engel & Schutt, 2012). The A-B-A design was chosen in this study due to three main reasons. First, this type of experimental design allows the changes before, during and after treatment to be observed. As a result, the PI can see what effect, if any, the CBCLBP programme had on the HLOC and other co-variables. Further, the treatment principle of the CBCLBP programme is based on the idea that the therapeutic effects will carry over following the programme (Hansen et al., 2010; Ostelo et al., 2005). By re-introducing the baseline condition (Phase A2) following treatment (Phase B) (see Figure 3.1), the effect of the CBCLBP programme may persist, and how long the effect of

CHAPTER 3 Methodology Page 82 the programme may persist up until six months post-intervention can be observed.

Secondly, the A-B-A design is ethically safe because all study participants received treatments. The CBCLBP programme received by the study participants is the routine care provided by the Physiotherapy Department for patients with NSCLBP. The only difference between the study participants to routine patients was that the study participants were asked to complete additional questionnaires, and were followed up until six months following the programme.

Finally and importantly, the normal physiotherapy service and patients’ waiting time were not compromised as a result of the A-B-A design because the routine waiting time for entering the CBCLBP programme was about 4 weeks on average. The PI also did the majority of the research work, and put in extra hours to recruit patients and collect data. Hence, no extra staffing was required.

Both are considered to be crucial by the NHS management and the Research and Development (R&D) of the Trust.

Comparing the A-B-A design to the basic A-B design, the A-B design only offers quick assessment of the programme by collecting measurements during the baseline phase (Phase A), and repeating the same measures during the intervention phase (Phase B) (Engel & Schutt, 2012). However, the A-B design does not provide any post-treatment follow up which examines if the effect of the CBCLBP programme persisted, and how long it may persist after patients stopped the intervention, which is the intention of this study.

The A-B-A-B design is similar to the A-B-A design, except that the A-B-A-B design reintroduces the intervention in the second intervention period, based on the assumption that the effect of the treatment may reverse by withdrawing intervention and there may be second improvement by reintroducing treatment.

Although the A-B-A-B design may give stronger support that changes between

CHAPTER 3 Methodology Page 83 no treatment and treatment phases are due to the intervention, and not due to the natural history of the condition (Engel & Schutt, 2012), there is no guarantee that the effect will be reversed, particularly because the CBA treatment is based on the practice theory that the therapeutic effect may carry over, and is designed to reduce the target problems without the need for ongoing intervention.

Therefore, the A-B-A-B design was not chosen.

3.3.4 Implications of the clinician-researcher dual role

Because of the resource issues, the PI had to act as both researcher and clinician. The PI was involved in gaining all informed consents, carried out the majority of the treatment, and collected all data at 3 months and 6 months post intervention. There is advantage and disadvantage of the PI being a clinician-researcher dual role in the current study. An advantage for having the PI to collect data helped to ensure data quality, and minimize missing data during follow-up. However, the disadvantage of this approach included the possibility of expectancy effect (Bootzin, 1985) and halo effect (Nisbett & Wilson, 1977), both factors would have influence on patients’ self- reported data on pain intensity, disability and perceived control (Klaber Moffett & Richardson, 1997). Besides, there is detection bias due to lack of blinding of outcome assessors. These limitations (which are discussed in Chapter 6) may reduce the internal validity of the findings. It is acknowledged that it would have been preferable for the PI to act as an independent researcher, with no input into treatment and data collection. However, this was not possible in the current study.