BACKGROUND: Periodontal disease is preventable but remains the most common oral disease worldwide, with major health and economic implications. Stakeholders lack reliable evidence of the relative clinical effectiveness and cost-effectiveness of different types of oral hygiene advice (OHA) and the optimal frequency of periodontal instrumentation (PI).
OBJECTIVES: To test clinical effectiveness and assess the economic value of the following strategies: personalised OHA versus routine OHA, 12-monthly PI (scale and polish) compared with 6-monthly PI, and no PI compared with 6-monthly PI.
DESIGN: Multicentre, pragmatic split-plot, randomised open trial with a cluster factorial design and blinded outcome evaluation with 3 years' follow-up and a within-trial cost-benefit analysis. NHS and participant costs were combined with benefits [willingness to pay (WTP)] estimated from a discrete choice experiment (DCE).
SETTING: UK dental practices.
PARTICIPANTS: Adult dentate NHS patients, regular attenders, with Basic Periodontal Examination (BPE) scores of 0, 1, 2 or 3.
INTERVENTION: Practices were randomised to provide routine or personalised OHA. Within each practice, participants were randomised to the following groups: no PI, 12-monthly PI or 6-monthly PI (current practice).
MAIN OUTCOME MEASURES: Clinical - gingival inflammation/bleeding on probing at the gingival margin (3 years). Patient - oral hygiene self-efficacy (3 years). Economic - net benefits (mean WTP minus mean costs).
RESULTS: A total of 63 dental practices and 1877 participants were recruited. The mean number of teeth and percentage of bleeding sites was 24 and 33%, respectively. Two-thirds of participants had BPE scores of ≤ 2. Under intention-to-treat analysis, there was no evidence of a difference in gingival inflammation/bleeding between the 6-monthly PI group and the no-PI group [difference 0.87%, 95% confidence interval (CI) -1.6% to 3.3%; p = 0.481] or between the 6-monthly PI group and the 12-monthly PI group (difference 0.11%, 95% CI -2.3% to 2.5%; p = 0.929). There was also no evidence of a difference between personalised and routine OHA (difference -2.5%, 95% CI -8.3% to 3.3%; p = 0.393). There was no evidence of a difference in self-efficacy between the 6-monthly PI group and the no-PI group (difference -0.028, 95% CI -0.119 to 0.063; p = 0.543) and no evidence of a clinically important difference between the 6-monthly PI group and the 12-monthly PI group (difference -0.097, 95% CI -0.188 to -0.006; p = 0.037). Compared with standard care, no PI with personalised OHA had the greatest cost savings: NHS perspective -£15 (95% CI -£34 to £4) and participant perspective -£64 (95% CI -£112 to -£16). The DCE shows that the general population value these services greatly. Personalised OHA with 6-monthly PI had the greatest incremental net benefit [£48 (95% CI £22 to £74)]. Sensitivity analyses did not change conclusions.
LIMITATIONS: Being a pragmatic trial, we did not deny PIs to the no-PI group; there was clear separation in the mean number of PIs between groups.
CONCLUSIONS: There was no additional benefit from scheduling 6-monthly or 12-monthly PIs over not providing this treatment unless desired or recommended, and no difference between OHA delivery for gingival inflammation/bleeding and patient-centred outcomes. However, participants valued, and were willing to pay for, both interventions, with greater financial value placed on PI than on OHA.
FUTURE WORK: Assess the clinical effectiveness and cost-effectiveness of providing multifaceted periodontal care packages in primary dental care for those with periodontitis.
TRIAL REGISTRATION: Current Controlled Trials ISRCTN56465715.
FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 38. See the NIHR Journals Library website for further project information.
The authors wish to thank Mark Forrest and the programming team at CHaRT; Cynthia Fraser, our information specialist, for assistance with referencing; Moira Swan, who was the dental research nurse and part of the OA team in Newcastle upon Tyne; Louise Campbell for secretarial support and data management; our original statistician in the group, Andy Elders; senior IT manager Gladys Macpherson; senior trial administrator at the TCOD Marilyn Laird; Luke Vale for his involvement with the design of the health economic analysis at the inception of the trial; Maria Dimitrova, who assisted the health economists in the collection of unit costs; staff of the Scottish Primary Care Research Network, who assisted with screening eligible patients at dental practices; staff of the North East Commissioning Support Unit who assisted with research payments to dental practices in the north-east; members of the TMC and Periodontal Advisory Group for their ongoing advice and support of the trial; the independent members of the TSC and DMC; and the staff at recruitment sites who facilitated recruitment, treatment and follow-up of trial participants.
The Health Services Research Unit and the Health Economics Research Unit is core funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorate.
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