RUBriefingPaperHEALTH ECONOMICS RESEARCH U NIT

Briefingpaperfor the NHS Sep 06

1 Theliterature on

Ozone treatment isstillat a relatively

early stage

COST-EFFECTIVENESSANALYSISOF'HEALOlONE'@FORTHETREATMENTOFOCCLUSALPIT/FISSURECARIESAND"ROOTCARIES

BackgroundDental caries are caused by the localised andprogressivedemineralisationof the hardtissuesof thecoronalandrootsurfacesof theteeth.- Thelocation,development,andprogressionof cariesdependuponarangeof environmental,social,andgeneticfactorsandvary greatly amongstindividuals. Almost 80% ofchildrenby theageof 18 and90% of adultswill havecaries. This is despitethe declinein the prevalenceobservedin many industrialisedcountriesduringthepast few decades. HealOzonehas been recentlyproposedas a novel method,which may reverse,

2 The effectiveness andcost-effectiveness ofHealOzone is not proven

3 HealOzone requiresfurther research evidence

to be generated beforeit could be

considered ascost effective

KeyMessages

arrest,or slowtheprogressionof dentalcaries.ThecompleteHealOzoneprocedureinvolvesthe directapplicationof ozonegasto thecarieslesionon thetoothsurfacebymeansof an HealOzonedevice,theuse of a re-mineralisingsolutionimmediatelyafterapplicationof ozone,andthesupplyof a 'patientkif,whichconsistsoftoothpaste,oralrinse,andoralsprayallcontainingfluoride.Thispaperpresentstheevidenceon the effectivenessand cost-effectivenessofHealOzoneforthemanagementofbothpitandfissurecariesandrootcaries.

I 4 9 5

Iej UNIVERSITY.OFABERDEEN

MethodsA systematicreviewof theeffectivenessof HealOzonefor the managementof toothdecaywas carriedout.Five full-text reportsand five studies publishedasabstractsonly metthe inclusioncriteria.Onlyonefulltext reportwas publishedin a refereedjournal,but itwas poorlyreported.TheremainingstudieswerePhDtheses, unpublished reports, or conferenceproceedings. Of the five studies published asabstracts,four assessedthe effectsof HealOzoneforthemanagementofocclusalcariesandonetheeffectsof HealOzonefor the managementof rootcaries. Asystematicreviewof existingeconomicevaluationsofozonefor dentalcarieswasalsoattemptedbutdespiteextensivesearching,nonewereidentified.

An economicmodelwasdevelopedto combinethebestavailabledataon effectivenesswith informationon cost in order to provideestimatesof cost-effectivenessof HealOzonepluscurrentmanagementrelativeto thestandardcurrentmanagementofdentalcaries.Themodelwasdesignedtoestimatea typicalpatient'scosts and outcomesfor the alternativetreatmentsovera five-yearperiod.Thefigurebelowsummarisesthebasicstructureofthemodel.

Figure1: Modelfor primarynon-cavitatedpit andfissurecaries

Initialtreatmentofearlycaries

Currentmanagement(watchfulwaiting,oral

hygiene/plaqueremoval,fluoride,sealants)

CurrentmanagementplusHealOzone

Reversalofcaries

Progressionofcaries

Reversalofcaries

Toothfilled Repeatof initialtreatment

Progressionof caries

Oneof the mainpiecesof datarequiredfor themodelwas the probabilitythat differentmanagementwouldresult in the reversal (cure) of caries. Theseprobabilitieswerederivedfromthe systematicreviewof effectiveness and consultation with dentalpractitioners.Thedatarelatingto annualprobabilityofcure were probablyvery unreliableas they werederivedfromonlyonesource.Indeedthe limiteddataavailablesuggestedthattheannualprobabilityof curewas 0.074 (7.4%) for the non-cavitatedpit andfissurecariesand 0.98 (98%) for the non-cavitatedroot cariesfollowingtreatmentwith HealOzone.Theratesforcurrentmanagementwere0.056 (5.6%), fornon-cavitatedpit andfissurecariesand0.01(1%) fornon-cavitatedrootcaries.

In the absenceof any alternativeinformation,it wasassumedfor thepurposesof themodelthat,followinginitialtreatment,therewas a 0.50 (50%) chancethatany subsequent treatment would be the sametreatment as the initial treatment e.g. a repeattreatmentwith HealOzone,or a filling. It was notpossibleto measurehealthbenefitsin termsof qualityadjustedlife years(QALYs).Thiswas partlybecausethe adverseeventsavoidedare transient- a fewsecondspain from injectionof local anaesthetic;theanxiety/fearof havingthe drill; numbnessuntil localanaesthesiawears off - but also the difficulty inestimatingreductionsin qualityof life causedby, forexample,toothache.

Resourceuse data were identified from existingliterature, reports from manufacturersand expertadvice. Based on existingevidenceand clinicalopinion, patientswere assumedto visit the dentistevery six months. Cost data were measuredinPoundsSterling(£) for the year 2004. An annualdiscountrateof 3.5% was appliedto bothcostsandbenefitsaccrued,theratecurrentlyspecifiedintheHTAguidelines.The per-itemfee for servicepaid by theNHSwas used as a proxyfor costs to the NHSofcurrentmanagement.Underthe currentNHSdentalsystempatientspay80% of thedentisrsfeewith theremaining20% beingpaidby theexchequer.

ResuItsAs some of the data requiredto estimate cost-effectivenessis verypooror, as in thecaseof qualityof life effects,not available,it was not possibletogenerate reliable results of cost-effectiveness.However,thetabledescribesthedataavailablefor themodel and it source. Thesedata havebeen'Trafficlighted'. Poordata,inwhichwe havelittleconfidence,

'\

Table1: Summaryof parametersusedin Model

Parameter

Annualratesof reversal

Value

areshadedred,datawhichwe aremoderatelyunsureof areshadedamberand reasonablyrobustdataareshadedgreen.

As this table illustrates,the data on effectivenessshouldbetreatedwith extremecaution,whilethedataon costsis generallybetterbutnotperfect.

Source

Costscurrentmanagement

Non-cavitatedpit andfissurecaries

Non-cavitatedrootcaries

CostscurrentmanagementplusHealOzone

Non-cavitatedpitandfissurecaries

£9.02

£6.09

£20.03

Non-cavitatedrootcaries £17.10

Restorativeinterventions

Filling £12.75

Reference$

NHSPublisheddata3

NHSPublisheddata3

NHSPublisheddata3andassumptionsaboutthecostof HealOzone

NHSPublisheddata3andassumptionsaboutthecostof HealOzone

NHSPublisheddata3

1. Abu-Naba'aLA Managementof primaryocclusalpit andfissurecariesusingozone.PhDThesis:Queen'sUniversityBelfast;2003.

2. HolmesJ. Clinicalreversalof rootcariesus.Ingozone,double-blind,randomised,controlled18-monthtrial.Gerodontology2003;20(2): 106.

3. Amendment92 to theStatementof DentalRemuneration[documenton the Internet]2004. UKDepartmentof Health[accessedJune2004].Availablefrom:http://www.dh.gov.uk/assetRoot/04/08/11/28/04081128.pdf

DiscussionCurrentlyHealOzoneis only availableto patientsthroughprivatedentalcare. Shouldits provisionbesupportedbytheNHS,thetotalcostof treatmentover5 yearswouldbe nearly£14 million,comparedto£8.6 million for currentmanagement. Thereisinsufficientevidenceat presenton the relativeeffectivenessof HealOzoneto indicatewhetheritwouldbe worthwhilefor the NHSto providesuchtreatment.Furtherresearchwouldbe necessarytofacilitatea completeeconomicevaluation. Suchresearchshouldfocus on reliablyestablishingtherelativeeffectivenessof HealOzonecomparedtocurrentmanagement.

CONTACTUS'. . .HEALTHECONOMICSRESEARCHUNITInstituteof AppliedHealthSciencesPolwarthBuildingForesterhillAberdeenAB252ZDTel:+44 (0) 1224-553480/553733Fax:+44 (0) 1224-550926Email:heru@abdn.ac.ukwww.abdn.ac.uk/heru

Forfurtherdetailsaboutthisstudysee:

M.Brazzelli, L.McKenzie,S.Fielding, C.Fraser,J.Clarkson,M.Kilonzo,and N.Waugh.Systematicreviewof the effectivenessandcost-effectivenessofHealOzone@for the treatmentof occlusalpit/fissurecaries and root caries. HealthTechnolAssess2006; 10(16): 1-9.

Theexecutivesummaryandfull textof the reportcanbe downloadedfrom the NHSR&DHTAProgrammeWebsite:http://www.hta.nhsweb.nhs.ukl.

Thisbriefingpaperdescribeswork conductedby theEconomicEvaluationProgrammeof HERUalongwiththe Departmentof Public Health. The work wascommissionedby colleaguesin the HealthServicesResearch Unit and the NHS Research andDevelopment Health Technology AssessmentProgramme,on behalf of the National InstituteofHealthand Clinical Excellence.Furtherinformationaboutthis topic can be obtainedby contactingMaryKilonzo, HERU,Universityof Aberdeen,Foresterhill,AB252ZD (tel: 01224 551906; e-mail:m.kilonzo@abdn.ac.uk).

HERUis supportedby the ChiefScientistOffice(CSO)of theScottishExecutiveHealthDepartment(SEHD).The views expressedhere are those of the authors and notnecessarilythoseof the CSQ,