The diffusion model (2.3) specifies the type and sequence of research required in assessing the value and applicability of a new healthcare technology before
dissemination for routine use. It identifies specific attributes for assessment at each level of research, which is useful in assessing complex healthcare interventions such as the RDT-based guideline. The Diffusion of innovation model is complimented by the Donabedian model of health systems performance (2.5.2) which shows the causal linkage between structural, process and outcomes attributes of quality.
Several levels and types of research are required in assessing a technology, from product development (phases 1 and 2) through to demonstration (phase 5). With regard to RDTs, extensive phase 1 and phase 2-level evaluations (product developments and the quality of manufacturing) have already taken place and are on-going (2.4). The current question is whether RDT-based guidelines can be effective in clinical settings and if they can be implemented sufficiently in clinical practice. Therefore, this thesis focuses on phase 3 through 5- level research (efficacy, effectiveness and implementation), basing on the current debates and theory.
A systematic review of RCTs was chosen to evaluate efficacy of the intervention because it was not feasible to undertake an RCT in the context of this thesis due to financial and time constraints. RCTs are considered the best design for attributing outcomes to an intervention. However, the literature suggests that RCTs are
characterised by several methodological limitations that may limit the power of RCTs to detect effects of a complex intervention. In particular, the Donabedian model of health systems performance suggests that the causal linkage between a complex public health intervention such as the one under evaluation, and clinical outcomes, is weak and may be difficult to demonstrate by means of an RCT. The thesis draws from this knowledge in discussing results of chapter 3 (assessment of efficacy) and in chapter 6 (general discussion). RCTs are also critcised for the potential threats to external validity of evidence. In the context of this thesis, knowledge of efficacy is necessary to aid interpretation of evidence from effectiveness trials. Therefore, this limitation is irrelevant. A systematic review has the advantage that it can pool together a variety of evidence from a broader context. As such, it might represent the best evidence for decision making at a broader level. Literature suggests that systematic reviews can lead to generalisable conclusions by identifying similar effects in various populations.
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In sub-section 2.5.5 the literature proposes a number of quasi-experimental designs which can be used in assessing effectiveness of an intervention, such as basic pretest- posttest design, control-group pretest-posttest design, and intervention versus control group comparison. The Ugandan effectiveness trial (chapter 4) used a control-group pretest-posttest design which is useful in assessing the role of maturation and history. Demonstration studies can show the extent to which various elements of a multi-
component intervention are actually implemented. In addition, it can identify key factors within the user system which can affect implementation of the policy in routine
practice—which may need to be investigated, or which may need to be addressed prior to or during wide-scale implementation (2.3). For example, guideline implementation may reflect structural challenges (e.g. availability of relevant inputs, support training and supervision, policies and patients' expectations). However, according to Donabedian model of systems performance (2.5.2), compliance with structural standards does not mean that high quality care is being provided; nor does their use in quality assessment imply that high quality care cannot be provided unless these standards are complied with. Knowledge of the validity of the causal linkage between structure, process and outcomes is useful in interpreting results of chapters 3, 4 and 5.
The literature describes implicit and explicit methods used in measuring HW performance, and indicates that explicit methods such as the LQAS are much more strict and action-oriented (2.5.2). LQAS method is used in chapter 5 to assess guideline implementation. The LQAS method has several advantages over implicit methods which measure quality in terms of point estimates (e.g. percent, averages). Judgement of quality is based on explicit pre-set standards, which allows the identification of poorly performing HWs or areas that require urgent action.
In section 2.7, the literature provides an overview of several biologic malaria diagnostics that have emerged over the last 100 years. Their application in rural clinical settings has been limited, mainly by technical capacity constraints and cost. Section 2.8 describes the RDT technology, types, factors influencing performance, performance in field trials, and the WHO product testing initiative. It provides an overview of factors affecting utility of an RDT-based policy in practice and reviews economic evaluation studies of RDT- based treatment relative to symptoms-based treatment. It shows that the potential effects of RDT-based policies depends on a number of factors, including the type of
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assay, its diagnostic accuracy, HW adherence, malaria endemicity, and population profiles. Several reviews indicate that RDTs may fail to achieve the desired sensitivity of 95% at parasite density of ≥ 100 parasite/100 µL of blood even under controlled trials conditions. Errors in using RDTs in routine practice could significantly exacerbate the diagnostic accuracy of RDTs. Use of RDT-based guideline is likely to be cost-saving and cost-effective if used in low to moderate malaria prevalence areas, as long as clinicians comply with the guidelines most of the time; and especially if RDT use is restricted to older patients. A fall in the price of anti-malarials may favour presumptive treatment. The effect of various factors on the utility of RDT-based policies was explored in the analysis in chapter 4. The influence of malaria endemicity informed the selection of districts (from both high and low prevalence districts) for the survey of practice in chapter 5.
Section 2.9 reviews implementation of guidelines in African context. Several studies indicate that the quality of guideline implementation varies widely. Studies vary in the components of guidelines assessed. Studies assessing fever-oriented guidelines
frequently focus on the quality of prescribing, which tends to overestimate the quality of implementation. Further, studies frequently use implicit measures of performance. Evidence from Africa also suggests that a variety of interventions can improve the quality of guideline implementation (2.10). The interventions consist of factors outlined in the diffusion of innovation and the Donabedian models and are usually assessed in surveys of fever-oriented guidelines. They have been assessed in the survey in chapter 5. Paraprofessional staff are likely to comply with clinical guidelines better than
professional staff. Support services such as in-service training and supervision are generally associated with improved HW adherence to guidelines. The effect of in-service training on guideline implementation appears to be short-lived; hence the need for refresher training and experiential learning. Availability of guidelines at facilities appears to have mixed effects on guideline implementation, while availability of essential drugs may to have no significant influence on guideline implementation.
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