The INCENTIVE Study: a mixed methods evaluation of an innovation in commissioning and delivery of primary dental care compared to traditional dental contracting.


Funded by NIHR Methods: MIHR Methods Programme


Whilst dentistry has long been incentivised; over the past decade commissioning of primary care dentistry has seen the introduction of refinements with contract currency evolving from payment for units of dental activity towards blended contracts that include incentives linked with key performance indicators such as access, quality and improved health outcome.


The aim of this study was to evaluate a blended/incentive-driven model of dental service provision. To:

  1. Explore stakeholder perspectives of the new service delivery model
  2. Assess the effectiveness of the new service delivery model in reducing the risk of and amount of dental disease and enhancing oral health related quality of life in patients
  3. Assess cost effectiveness of the new service delivery model in relation to oral health related quality of life


A mixed methods approach was used. The study included three dental practices working under the blended/incentive-driven (INCENTIVE) contract and three working under the units of dental activity (TRADITONAL) contract. All were based in West Yorkshire. The qualitative study reports on the meaning of key aspects of the model for three discrete stakeholder groups, with framework analysis of focus group and semi-structured interview data. A non-randomised study compared effectiveness and cost effectiveness of treatment under the two different contracts. The qualitative study included lay people (patients and non-patients (individuals without a dentist)), commissioners and the primary care dental teams. The quantitative study recruited 550 patients aged 16+ across the six practices. The primary outcome was gingivitis measured using bleeding on probing. Secondary outcomes included oral health related quality of life and cost effectiveness. Results

Participants in the qualitative study associated the INCENTIVE contract with more access, greater use of skill mix and improved health outcomes. Of 550 participants recruited, 291 attended baseline and follow up. Given missing data and following quality assurance, 188 were included in the bleeding on probing analysis, 187 in the caries assessment and 210 in the economic analysis. The results were mixed. The primary outcome, gingivitis using bleeding on probing favoured the INCENTIVE practices whilst the assessment of caries favoured the TRADITIONAL practices. Within the economic analyses INCENTIVE practices attracted a higher cost for the service commissioner but were financially attractive for the dental provider at the practice level. Differences in generic health related quality of life were negligible although positive changes over time in oral health related quality of life in both groups were statistically significant.  


Although there is some re-assurance that the effect size for the primary outcome is similar to that included in the original power calculation, the results of the quantitative analysis should be treated with caution given small sample numbers, reservations about the validity of pooling,  differential drop out results and data quality issues.


A large proportion of people in this study who had access to a dentist did not follow up on oral care. These individuals are more likely to be younger males and have poorer oral health. Whilst access to dental services was increased in as much as all participants were new patients, this did not appear to facilitate continued use of services.

Future Work

Further research is required to understand how best to promote and encourage appropriate dental service attendance especially amongst those with high level of need to avoid increasing health inequalities; and to assess the financial impact of the contract and particularly the increase of skill mix on the individual practitioner in order to support the model.  For dental practitioners the data hint at appreciable challenges related to a general refocussing of care and especially to perceptions about preventive dentistry and use of the risk assessments and care pathways. There are also obstacles to overcome to realise any benefits of the greater deployment of skill mix.

Publications and outputs

Hulme, Claire, et al. "Shaping dental contract reform: a clinical and cost-effective analysis of incentive-driven commissioning for improved oral health in primary dental care." BMJ open 6.9 (2016): e013549.

Pavitt, Sue H., et al. "The INCENTIVE protocol: an evaluation of the organisation and delivery of NHS dental healthcare to patients—innovation in the commissioning of primary dental care service delivery and organisation in the UK." BMJ open4.9 (2014): e005931.