Abstract
Periodontal disease is a highly prevalent but largely preventable non-communicable diseases with a high health and economic burden including pain, discomfort, tooth loss, reduced quality of life, and has a negative impact on confidence and financial cost implications. The direct global treatment costs in 2010 were estimated to be $298B with further indirect costs (lost productivity) of $144B annually.Despite an improved understanding of the aetiopathogenesis of periodontal disease, as well as evidence demonstrating that successful long-term prevention and treatment of periodontal disease is possible, there is still clinical uncertainty as to the most effective self-care regime, professional interventions and health care delivery models. Dental research has not always translated into a health benefit for patients or improvement in the evidence base and there are a number of limitations to the existing evidence base that have caused research wastage.
This thesis identifies and overcomes challenges experienced in randomised controlled trials and systematic reviews in periodontal research. The narrative review provides an overview of the current understanding of the aetiopathogenesis and epidemiology of periodontal disease as well as a description of the prevention and management treatment options. This review demonstrated that inappropriate research questions, participants, interventions and outcome choices in primary research combined with out of date systematic reviews with questionable transparency have led to the clinical uncertainty in optimal care delivery.
Four Cochrane systematic reviews were carried out to identify the challenges experienced in conducting randomised controlled trials and systematic reviews of ‘real world’ preventive and management interventions for periodontal disease. Two of these interventions form part of many patients’ individual self-care (Triclosan and Chlorhexidine) and the other two are predominantly delivered by dental professionals on a daily basis in primary dental care (One to one oral hygiene advice and routine scale and polish).
A number of challenges were identified (and experienced) including issues related to: (1) poor trial reporting; (2) inappropriate populations and settings; (3) inappropriate interventions; (4) inadequate follow-up times; (5) heterogeneous outcome measures and indices; and (6) lack of consensus within the profession about what would constitute a ‘clinically meaningful’ or ‘patient significant’ improvements.
Challenges (1) to (4) are being addressed by a number of initiatives like CONsolidated Standards Of Reporting Trials (CONSORT), PRagmatic Explanatory Continuum Indicator Summary (PRECIS-2), Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) and the Template for Intervention Description and Replication (TIDieR) amongst others.
Prior to determining what would constitute meaningful results to dental professionals and patients the outcomes of importance to these groups needed to be established. To meet the challenge of heterogeneous outcomes that cause research wastage a core outcome set for effectiveness trials investigating prevention and management interventions for periodontal disease was required.
This core outcome set was developed by following the methodological framework identified by the COMET initiative (Williamson et al., 2017). The literature review conducted to complete stage (i) identify existing knowledge of outcomes in effectiveness trials pragmatically focused on Cochrane Systematic reviews and protocols. This review identified 37 unique outcomes from eight Cochrane systematic reviews (including 134 unique studies and 23,276 participants) and three protocols. The 37 outcomes identified were brought forward to the consensus process.
Two consensus methods (‘e-Delphi process’ and ‘face to face consensus meeting’) were combined to effectively meet the COMET initiative’s stages: (ii) Filling gaps in knowledge and (iii) Eliciting views about important outcomes in a consensus process and (iv) Holding a face to face meeting to finalise the recommended core outcome set.
The e-Delphi process involved 71 participants (20 patient participants and 51 dental professionals and researcher participants) who prioritised 22 outcomes to be taken forward to the face to face meeting.
The face to face consensus meeting held in Dundee involved 14 participants (8 patients and 6 dental professionals and researchers) discussing these 22 outcomes in a modified Nominal Group Technique meeting prior to selecting the core outcome set. In alphabetical order the five outcomes proposed by the key stakeholder groups are: ‘Probing depths’, ‘Quantified levels of gingivitis’, ‘Quantified levels of plaque’, ‘Quality of life’ and ‘Tooth loss’. This core outcome set can be used in future randomised controlled trials and systematic reviews to reduce outcome heterogeneity and improve the evidence creation and synthesis process. If implemented these improvements should ultimately improve patient care.
| Date of Award | 2018 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Janet Clarkson (Supervisor), David Ricketts (Supervisor) & Craig Robert Ramsay (Supervisor) |