Cost-effectiveness of periodontal management in diabetes patients

Background + Aims

• There is increasing evidence linking periodontal inflammation to elevated glycated haemoglobin (HbA1c) levels in patients with type 2 diabetes mellitus (T2DM). Periodontal disease is more prevalent in those with T2DM and contributes to chronic inflammation, potentially raising HbA1c levels. Persistently high HbA1c can lead to severe complications such as cardiovascular disease, blindness, amputations, renal failure, and premature death.
• Current clinical guidelines for T2DM management omit periodontal disease, focusing instead on controlling blood glucose, blood pressure, and managing other known diabetic complications. Managing periodontal disease involves significant long-term costs but may benefit T2DM patients by improving glycaemic control and oral health.
• This study evaluates the cost-utility of non-surgical periodontal therapy in newly diagnosed T2DM patients with periodontitis, using Quality Adjusted Life-Years (QALYs) as a measure of effectiveness. The study compares cost-effectiveness estimates with UK thresholds for acceptable interventions, emphasising the potential health and economic benefits of incorporating periodontal care into T2DM management.

Materials + Methods

• The study developed a spreadsheet model to evaluate the lifetime cost-effectiveness of non-surgical periodontal therapy for patients with newly diagnosed T2DM and periodontal disease.
• The model compared two scenarios: non-surgical periodontal treatment with lifetime maintenance and no periodontal treatment (routine scale and polish only). It incorporated costs of periodontal treatment, maintenance, and tooth replacement, alongside health savings from reduced HbA1c levels and their impact on quality-adjusted life years (QALYs).
• The base case considered patients with life expectancies at time of diagnosis as 8, 17, and 28 years remaining.
• Periodontal treatment was assumed to be delivered in two 60-minute sessions with an experienced practitioner, with 30-minute maintenance appointments 3-monthly with a hygienist. Retreatment was assumed to be required once every 3-years.
• The model used published data on the reduction of HbA1c levels following periodontal therapy, assuming a conservative 0.29% reduction sustained in compliant patients. Costs were calculated from a healthcare provider perspective, accounting for initial treatment, maintenance, and re-treatment every three years, with compliance set at 30%. Tooth loss rates and replacement costs were based on existing studies. With the majority of patients assumed to be non-compliant with maintenance, they would incur the costs of initial treatment only and not the sustained health benefits.
• Estimated costs for periodontal therapy and restorative dental care were analysed from a provider perspective. The UK’s publicly funded dental care is remunerated by Units of Dental Activity (UDAs), with periodontal treatment attracting three UDAs (£75). However, the actual provider costs were estimated higher, at £207 per hour for periodontal therapy, reflecting salaries, overheads, and associated practice expenses. Restorative care costs, such as tooth replacement, were estimated at £167 per hour for performers and £56 per hour for hygienists. Laboratory costs for prosthetics and procedure times for extractions, dentures, and resin-bonded bridges were included. The mean cost for tooth loss replacement was £295, reduced to £181 after factoring patient co-payments. Sensitivity analyses excluded co-payment costs and explored cost variations. This approach ensured a comprehensive assessment of treatment costs and their financial implications for the healthcare system.
• Sensitivity analyses explored variations in treatment costs, compliance, HbA1c reduction, and tooth loss rates.
• Results were reported as incremental cost-effectiveness ratios (ICERs), comparing costs per QALY gained against UK thresholds (£20,000–£30,000 per QALY). The findings assessed whether periodontal therapy provides a cost-effective strategy to improve health outcomes and reduce diabetes-related complications.

Results

• The base case analysis revealed that while periodontal treatment leads to modest cost savings from reduced HbA1c levels and tooth loss, the total treatment costs remain higher than the control arm.
• Quality Adjusted Life Year (QALY) gains were modest, as many patients were assumed to fail in maintaining compliance with treatment.
• Incremental Cost-Effectiveness Ratios (ICERs) ranged from £11,000 to £35,000 per QALY, with greater cost-effectiveness observed in patients with higher baseline HbA1c levels and older patients, as their lifetime treatment costs were lower. However, the model assumed age-independent health gains, which may overestimate benefits for older individuals.
• ICERs remained below the £30,000 per QALY threshold for all subgroups, except younger patients with baseline HbA1c levels of 7–8.9%.
• Sensitivity analysis highlighted significant uncertainty in the results, particularly regarding reductions in HbA1c, compliance rates, and treatment responsiveness.
• Parameters such as health cost savings from HbA1c reduction, tooth replacement costs, and tooth loss rates in compliant patients had minimal impact on ICERs. Excluding patient co-payments slightly reduced treatment costs but did not meaningfully alter overall ICERs.

Limitations