direct access dr paul brocklehurst senior clinical lecturer & nihr clinician scientist bds, bsc,...

Direct Access

Dr Paul Brocklehurst

Senior Clinical Lecturer & NIHR Clinician Scientist

BDS, BSc, MDPH, PhD, FFGDP, FHEA, FDS RCS (Eng)

Learning outcomes

• Understand the evidence for:

– Comparative diagnostic test accuracy of DCPs and GDPs when screening for caries, PD & oral cancer

– The latest Effective Practice and Organisation of Care review on dental auxiliaries

– Current research into the productivity of using DCPs to undertake role-substitutive tasks

Changing face of medicine

Lessons from medicine

Impact of the QOF

Overarching principles

Low variability

High variability

Low complexity High complexity

Nurse-led

Multi-professional team

Multi-professional clinic

Nurse & doctor

Traditional model

Office of Fair Trading

• Is the UK dentistry market working for consumers?

– can consumers assess and act on provided information

– level the playing field between providers in the dental market

Argues for the lifting of restrictions

• “The OFT considers these restrictions to be unjustified and likely to reduce patient choice and dampen competition”

• “The OFT urges the General Dental Council to remove restrictions preventing patients from making appointments to see dental hygienists…and dental therapists”

GDC’s decision

• “From today, patients can book directly with a dental hygienist or dental therapist who offers a direct access service”

28th March 2013

“Direct access” model

Independent practice in Europe

Country Year

Sweden 1964

Netherlands 1978

Finland 1994

Denmark 1996

Switzerland 1997

Italy 1999

Norway 2001

The NHS (PL) Regulations 2004

• To get a GDS or PDS contract….

….you need a Performers List

number

• DCPs can’t hold a PL

Other “buts”…

• Ionising Radiation (Medical Exposure) Regulations 2000 do not recognise DCPs as prescribers (only operators)

• At present, GDC state that the dentist remains the only member of the dental team who can prescribe radiographs

Other “buts”…

• LA is POM which means that under the Medicines Act 1968 it can only be prescribed by a qualified prescriber – dentist

• DCPs can administer, but only under a written, patient-specific prescription or under a Patient Group Direction (PGD) - written instruction

Other “buts”…

• Fluoride is a POM

• Fluoride can only be prescribed under a PDG

• Written instruction without the need for being patient-specific

• DCPs can’t prescribe

Other “buts”…

• DCPs cannot provide tooth whitening direct to patients - first application must be done by a dentist and subsequent on prescription. The Council is not in a position to change this

• Not in the practice of dentistry, but it is a POM

So where do we go from here?

Change to a capitation system

2015

Capitation

• £50 per patient; patient list of 7,500

• Sales (income) = £375,000 £375,000

• Cost of sales = £250,000 £150,000

• Profit = £125,000 £225,000

What are the new incentives?

• Do the same clinical activity for less cost?

• Do less clinical activity?

• Cream-skimming

• Dumping

• Utilisation of role-substitution

Impact of impending capitation

Overarching principles

Low variability

High variability

Low complexity High complexity

Nurse-led

Multi-professional team

Multi-professional clinic

Nurse & doctor

Population health increasing

Overarching principles

Low variability

High variability

Low complexity High complexity

Nurse-led

Multi-professional team

Multi-professional clinic

Nurse & doctor

What is the evidence?

UoM research programme

• In vitro diagnostic test accuracy study (caries)• In vivo diagnostic test accuracy study (caries)• In vitro diagnostic test accuracy study (PMD)• Feasibility study on the use of DCPs in dentistry• EPOC review on the use of DCPs in dentistry• Policy analysis of DA in the Netherlands• Systematic review of DA• Technical efficiency of role-substitutive models

in dentistry

Predicted as diseased (positive)Diseased – True PositiveHealthy – False Positive

Sensitivity is how well the test identifies those in the population with the disease

[ = 5 / 6 ]

Specificity is how well the test identifies those in the population who are healthy

[ = 7 / 9 ]

1. Healthy

2. Suspected decay

How would you score this tooth?

Short 5m training exercise

102 teeth to score

Teeth sectioned – answer

All the dental team

How did dental students perform?

Sensitivity Specificity

Dental students

.85 .65

Were experienced dentists better?

Sensitivity Specificity

Dental students

.85 .65

GDPs .85 .71

What about hygiene therapists?

Sensitivity Specificity

Dental students

.85 .65

GDPs .85 .71

HTs .85 .67

What about H-T students?

Sensitivity Specificity

Dental students

.85 .65

GDPs .85 .71

HTs .85 .67

HT students .85 .54

And Dental Nurses…

…and the results were surprising!

Sensitivity Specificity

Dental students

.85 .65

GDPs .85 .71

HTs .85 .67

HT students .85 .54

Dental Nurses .88 .62

….after 5m training!

Dental nurses

Sensitivity Specificity

Dental students

.85 .65

GDPs .85 .71

HTs .85 .67

HT students .85 .54

Dental Nurses .88 .62

Out of the diseased teeth examined, 88% were correctly predicted to have disease

Out of the healthy teeth Examined, 62% were correctlypredicted to be Healthy

Comparative efficacy in vitro

UoM research programme

• In vitro diagnostic test accuracy study (caries)• In vivo diagnostic test accuracy study (caries)• In vitro diagnostic test accuracy study (PMD)• Feasibility study on the use of DCPs in dentistry• EPOC review on the use of DCPs in dentistry• Policy analysis of DA in the Netherlands• Systematic review of DA• Technical efficiency of role-substitutive models

in dentistry

Diagnostic Test Accuracy (DTA) Study

• Index Test – Dental Care Professionals (DCPs) will perform a screen for caries and periodontal disease.

• Reference Test – General Dental Practitioner (GDP) independently performs an identical screening process

Index test positive

• Any tooth with frank cavitated lesions or any tooth with shadowing or opacity consistent with underlying dentinal caries

Index test positive

• Probing depth of any site on any tooth causes the BPE probe to disappear so that the black band is only partially visible (BPE 3) or disappears (BPE 4)

• Not about BoP

Identify Practices

Train DCP, GDP & Practice Manager

Recruit patients

Pre attendance

Attendance

Formal Consent

YesDCP

GDP

Record forms

NoGDP

DCP

Check upGDP

Check up

GDP

Index test negative

Could DCPs be the gatekeeper?

Caries 

Sensitivity 0.82

Specificity 0.93

PPV 0.82

NPV 0.93

Periodontal disease 

Sensitivity 0.89

Specificity 0.84

PPV 0.83

NPV 0.91

Could DCPs be the gatekeeper?

Caries 

Sensitivity 0.82

Specificity 0.93

PPV 0.82

NPV 0.93

Identifies 82% with disease (18% FNs) 

Identifies 93% who are healthy (7% FPs) 

Could DCPs be the gatekeeper?

Identifies 89% with disease (11% FNs) 

Identifies 84% who are healthy (16% FPs) 

Periodontal disease 

Sensitivity 0.89

Specificity 0.84

PPV 0.83

NPV 0.91

Cumulative results - caries

Cumulative results - PD

UoM research programme

• In vitro diagnostic test accuracy study (caries)• In vivo diagnostic test accuracy study (caries)• In vitro diagnostic test accuracy study (PMD)• Feasibility study on the use of DCPs in dentistry• EPOC review on the use of DCPs in dentistry• Policy analysis of DA in the Netherlands• Systematic review of DA• Technical efficiency of role-substitutive models

in dentistry

Screening for oral cancer

• Short 5m training and orientation exercise

• GDPs and DCPs across four centres [+ Netherlands]

• Diagnostic test accuracy methodology– Index test = visual screen of clinical vignettes– Target condition = oral cancer and PMDs– Reference standard = histological confirmation

• Presented as summary hierarchical ROC - each point representing the point estimate for sensitivity and specificity for each participant (based on mean values)

The problem

• Two-sided 95.0% confidence interval for a single proportion (sensitivity or specificity) using a z-test approximation on an expected observed proportion of 0.90:

[n ‡ (Z2⁄m2) * p(1 – p)] = 35

• Usual procedure in DTA studies is to multiply the power calculation by the reciprocal of the prevalence:

n * 100 / prevalence = n.

[effect size of 0.1; power of 0.8]

The problem

• Prevalence of positive lesions in general dental practice is 4.2% (Lim et al., 2003) and would require over 700 photographs if population was modeled

• So we asked participants to screen PMD / oral cancer from a population of malignant and benign lesions

– 35 photographs of oral malignancy or PMD (positive lesions)

– 48 (9.9%-4.2% / 4.2% * 35) photographs of benign lesions

Lim K, Moles DR, Downer MC, Speight PM. Opportunistic screening for oral cancer and precancer in general dental practice: results of a demonstration study. Br Dent J 2003; 194: 497–502

How would you score this lesion?

5 ….and how confident are you?

Results - specialists?

Sensitivity Specificity Confidence

Specialists 0.85 0.74 6.62

Results - GDPs?

Sensitivity Specificity Confidence

Specialists 0.85 0.74 6.62

GDPs 0.80 0.68 6.29

Results - DCPs?

Sensitivity Specificity Confidence

Specialists 0.85 0.74 6.62

GDPs 0.80 0.68 6.29

DCPs 0.81 0.65 6.36

Summary ROCs

Should this surprise us? …No

• The longest running and only randomised controlled trial used trained health care workers and results at three, six and nine years have demonstrated their efficacy (Sankaranarayanan et al., 2005; Subramanian et al.,2009).

• Results from other studies using DCPs report values of 93.3% for sensitivity and 94.3% for specificity (Sankaranarayanan, 1997)

Brocklehurst P, Kujan O, Glenny AM, Oliver R, Sloan P, Ogden G, Shepherd S.Screening programmes for the early detection and prevention of oral cancer. Cochrane Database of Systematic Reviews 2010, Issue 11.

UoM research programme

• In vitro diagnostic test accuracy study (caries)• In vivo diagnostic test accuracy study (caries)• In vitro diagnostic test accuracy study (PMD)• Feasibility study on the use of DCPs in dentistry• EPOC review on the use of DCPs in dentistry• Policy analysis of DA in the Netherlands• Systematic review of DA• Technical efficiency of role-substitutive models

in dentistry

Potential models - sandwich

Potential models - gatekeeper

False positives (over-referrals)

• False positives are not a problem as they will be seen by the dentist and identified as healthy

• From a health economic perspective, this won’t be a problem if the numbers are relatively small

False negatives (undetected disease)?

• False negatives should also be considered in the context of routine attendance, where patients would be seen again

• Dental caries is a slow growing disease in many cohorts and so a false negative of itself is not “life threatening”

What about undetected disease?

Broadbent JM, Thomson WM, Poulton R. Trajectorypatterns of dental caries experience in the permanent dentition to the fourth decade of life. J Dent Res 2008;87:69–72

Changes to SoP

Changes to SoP

• “Carry out a clinical examination within their competence”

• “Diagnose and treatment plan within their competence”

UoM research programme

• In vitro diagnostic test accuracy study (caries)• In vivo diagnostic test accuracy study (caries)• In vitro diagnostic test accuracy study (PMD)• Feasibility study on the use of DCPs in dentistry• EPOC review on the use of DCPs in dentistry• Policy analysis of DA in the Netherlands• Systematic review of DA• Technical efficiency of role-substitutive models

in dentistry

Refreshing Galloway

• Galloway et al’s review of DCPs for diagnosing caries:

– Sensitivity ranged from .71 to .94

– Specificity from .94 to .97

Refreshing Galloway

• Identified 1 cluster RCT, 2 RCTs and 1 NRCT comparing effectiveness in FSs and ART

• Risk of bias high and GRADE very low

• No difference between GDPs and DCPs

• Paucity of high quality studies and no firm conclusions

Dyer T, Brocklehurst P, Glenny A-M, Davies L, Tickle M, Robinson PG. Dental auxiliaries for dental care. Cochrane Database of Systematic Reviews 2012, Issue 9. Art. No.: CD010076.

UoM research programme

• In vitro diagnostic test accuracy study (caries)• In vivo diagnostic test accuracy study (caries)• In vitro diagnostic test accuracy study (PMD)• Feasibility study on the use of DCPs in dentistry• EPOC review on the use of DCPs in dentistry• Policy analysis of DA in the Netherlands• Systematic review of DA• Technical efficiency of role-substitutive models

in dentistry

Policy analysis and review of DA

• Semi-structured interviews and focus groups were undertaken with thirty policy makers and clinicians in the Netherlands.

• “Working relationships within integrated practices in the Netherlands are positive, but attitudes towards independent practice are mixed. Good examples of collaborative working across practices was observed”

Northcott A , Brocklehurst PR, Jerkovic K, Reindeers J-J, McDermott I, Tickle M. Direct access: lessons learnt from the Netherlands. Br Dent J 2013 (accepted)

Policy analysis and review of DA

• 371 records identified although the extent of experimental evidence was limited (one study)

• Majority descriptive and recorded the subjective views of stakeholders

• “Extent of experimental evidence regarding DA contrasts with their wide-spread use across Europe, the US and the Southern Hemisphere”

Brocklehurst PR, Mertz B, Jerkovic K, Littlewood A, Tickle M. Direct Access to Dental Care Professionals: an evidence synthesis. Comm Dent Oral Epidemiol (submitted)

UoM research programme

• In vitro diagnostic test accuracy study (caries)• In vivo diagnostic test accuracy study (caries)• In vitro diagnostic test accuracy study (PMD)• Feasibility study on the use of DCPs in dentistry• EPOC review on the use of DCPs in dentistry• Policy analysis of DA in the Netherlands• Systematic review of DA• Technical efficiency of role-substitutive models

in dentistry

Aim

• The aim of this programme of research is to determine the productivity (technical efficiency) of role-substitution between GDPs and DCPs in high-street dental practices in the NHS in the UK

• Determine whether this is influenced by the incentives within the NHS remuneration system

• Examine barriers and enablers to the greater use of role-substitution in a NHS practices

Productivity

Productivity

Productivity

Workstream One

• Technical efficiency of differing models:

– Inputs = the number of NHS Clinical Hours worked

– Outputs = clinical activity produced by the team

– Data envelopment analysis

– Stochastic Frontier Modeling

• DEA is a linear model (few assumptions)

• SFM is a parametric model c.f. regression

• Models divided into:– Efficient– Inefficient – Indifferent

Workstream Two

• Stratified purposive sample based on efficiency

• Semi-structured interviews by embedded qualitative researcher:– practice owner– DCP– patient

• Methodology– Interviews transcribed into

Nvivo– Constant comparative

analysis– Continue until saturation– Thematic analysis

• Richer understanding of using DCPs in different team designs

Summary

• Two components of ‘efficiency’ will be examined:– How well each practice contains costs– How productive they are (dental services provided)

• To determine how observed efficiency depends on the way practices have been organised

• Account for confounders:– Patient case-mix (e.g. children)– Geo- and demographic factors (e.g. IMD, DMFT)

Thank you