!∀
#∃%&∋()∗
+
!
,%−(
./!∃!
,∋0
1
HEDS Discussion Paper 07/06
Disclaimer:
This is a Discussion Paper produced and published by the Health Economics
and Decision Science (HEDS) Section at the School of Health and Related
Research (ScHARR), University of Sheffield. HEDS Discussion Papers are
intended to provide information and encourage discussion on a topic in
advance of formal publication. They represent only the views of the authors,
and do not necessarily reflect the views or approval of the sponsors.
White Rose Repository URL for this paper:
http://eprints.whiterose.ac.uk/10913/
Once a version of Discussion Paper content is published in a peer-reviewed
journal, this typically supersedes the Discussion Paper and readers are invited
to cite the published version in preference to the original version.
Published paper
None.
White Rose Research Online
[email protected]
-1-
-2-
ScHARR
Health Economics and Decision Science
Discussion Paper Series
No. 07/06
INCLUDING PATIENT CHOICE IN COSTEFFECTIVENESS DECISION RULES
Simon Dixon1
1.
Health Economics and Decision Science, School of Health and Related
Research, University of Sheffield.
Corresponding author:
Dr Simon Dixon
HEDS, ScHARR, University of Sheffield
Regent Court, 30 Regent Street, Sheffield, UK, S1 4DA
Tel: +44 (0) 114 2220724
Fax: +44 (0) 114 2224095
email : [email protected]
Abst r act
There has been increasing discussion in t he econom ic lit erat ure, about the
appropriat eness of using general populat ion values wit hin t echnology appraisal.
This paper proposes an alt ernat ive approach t o incorporat ing pat ient values int o
t he cost - effect iveness decision rule t hat lies at the heart of funding decisions.
Whilst t he current decision rule is const ruct ed around a t echnical quest ion,
nam ely, ‘which t reat m ent is t he m ost cost - effective?’, the key policy question is
‘which t reat m ent s should be offered t o t he pat ient ?’. A t wo- part decision rule is
explored which gives t he pat ient t he choice of t he m ost cost - effect ive t reat m ent
plus all cheaper opt ions. Whilst t he adopt ion of t his pat ient - based cost effectiveness rule m ay not alt er m any decisions com pared t o t he current
approach, it would represent a profound shift in t he way that pat ient values and
pat ient choice are incorporat ed int o econom ic evaluat ion.
Ba ck grou n d
Purchasers of healt h care across t he world increasingly m ake decisions about
which t reat m ent s can be used by pat ient s using cost - effect iveness considerat ions.
Wit hin t his fram ework, effect iveness is m ost frequent ly m easured using qualit yadj ust ed life years ( QALYs) . QALYs are calculat ed by sum m ing m orbidit y
weight ed life- expect ancy, wit h the weight s t ypically based around m ean values
generat ed from a sam ple of t he general populat ion. The weight s represent
valuat ions of healt h- relat ed well- being ( or ut ilit y) , and are anchored on 1
( represent ing full-healt h) and 0 (represent ing deat h or healt h st at es considered
t o be equivalent t o deat h) .
There has been increasing discussion in t he econom ic lit erat ure, about the
appropriat eness of using these general populat ion values wit hin t echnology
appraisal (Brazier et al., 2005) . I t is argued, by som e, t hat pat ient values are
bet t er est im at es of healt h- relat ed well- being as pat ient s have first hand
experience of t he healt h st at e. Describing a part icular healt h st at e, t hen asking a
m em ber of the general public t o place a value on it , is pot ent ially flawed by t he
lim it at ions of the descript ive syst em used t o describe t he healt h st at e and the
abilit y of a m em ber of public t o im agine what it is like t o be in that healt h st at e.
Given t hese problem s, it is lit t le wonder t hat large differences bet ween pat ient
and public values are observed.
Despit e t hese problem s, t he use of general populat ion values cont inue t o
dom inat e t echnology appraisals, alt hough t he reasons for t his t end t o focus on
t he pot ent ial disadvant ages of using pat ient values. One group of influent ial
econom ist s argued t hat societ y should adopt a ‘veil of ignorance’ when choosing
healt h st at e values t o purposely avoid the influence of self int erest (Gold et al.,
1996) . Such self int erest , it has been argued, can lead t o st rat egic behaviour
when collect ing healt h values. Anot her problem avoided by the use of populat ion
values is t hat som e aspect s of pat ient values m ay want t o be excluded from our
valuat ion of healt h out com es. Adapt at ion, it is argued can lead t o pat ient s being
sat isfied wit h t heir dim inished funct ioning, t hus leading t o higher t han expect ed
values, and conversely, lower t han expect ed gains from t reat m ent .
The disquiet around the problem s wit h general populat ion values has led t o calls
for using bet t er inform ed general populat ion values. Such values are seen as
having t he benefit s of m aint aining a social perspect ive, wit h fewer of t he
1
problem s associat ed wit h t heir lack of experient ial knowledge. Whilst t here is an
increasing am ount of work around pat ient values, and t heir role wit hin t echnology
appraisal, t he cost - effect iveness decision rule t hat lies at t he heart of funding
decisions has rem ained unquest ioned.
Th e cu r re n t cost - effe ct ive ne ss ru le
The cost -effect iveness rule used rout inely in t echnology appraisal is t hat for any
given m onet ary value placed on healt h ( or a QALY) , t he recom m ended t reat m ent
for funding is ident ified as t hat wit h t he highest increm ent al cost - effect iveness
rat io ( I CER) t hat falls beneat h t his threshold value 1 .
This cost - effect iveness rule can be illust rat ed using Table 1. ‘Do not hing’
represent s a sit uat ion where no act ive t herapy is given t o t he pat ient , t reat m ent s
‘A’, ‘B’ and ‘C’ are new, m ore expensive therapies. Using t he current decision
rule, and a t hreshold value of £30 000 per QALY, we see t hat t reat m ent A is
deem ed the m ost cost - effect ive, and is t herefore recom m ended for pat ient s wit h
t he condit ion.
Ta ble 1 : Cost - e ffe ct iven e ss of fou r h ypothe t ica l t r e a t m en t choices
Treat m ent
C
A
B
Do not hing ( DN)
Cost
QALYs
I ncrem ent al cost effectiveness rat io
relat ive t o DN
100 000
50 000
20 000
1 000
5.5
5.0
3.5
3.0
39 600
24 500
38 000
I ncrem ent al cost effectiveness rat io
relat ive t o next
best opt ion
100 000
20 000
38 000
However, the current decision rule is const ruct ed around a t echnical quest ion,
nam ely, ‘which is t he m ost cost - effect ive t reat m ent ?’, when the quest ion t hat
should be asked is ‘which t reat m ent s should be offered t o t he pat ient ?’. Under
t he current rule, som e pat ient choice rem ains as a pat ient can not be forced t o
accept t he therapy deem ed m ost -cost -effect ive; t hey act ually have t he choice of
‘Do not hing’ and ‘A’. However, som e pat ient s m ay prefer t reat m ent ‘B’ over
t reat m ent ‘A’, but are not allowed t his under t he decision rule, even t hough it is
expect ed t o cost less t han A. 2
This sit uat ion is produced because m ean ex post general populat ion values and
ex ant e individual pat ient values rank t he t reat m ent s different ly; populat ion
values suggest t hat t reat m ent ‘A’ is preferred, whilst pat ient values suggest t hat
t reat m ent ‘B’ is preferred. I t also produces an inconsist ency wit h respect t o t he
im plied pat ient choice wit hin t he current decision rule; pat ient s are able t o choose
one t reat m ent which cost s less but is deem ed less effect ive based on m ean
general populat ion values (i.e. ‘Do not hing’) , but not anot her ( i.e. ‘B’) .
1
Although the decision rule should relate to the increment relative to the next best option, the rule is
frequently operationalised with the increment relating to ‘do nothing’ or ‘current treatment’.
2
The position of treatment A is recognised by economists in terms of ‘extended dominance’
(Weinstein 1990), a concept that is used to rule out the treatment from further consideration as a
potentially cost-effective treatment.
2
Whilst t his is an int erest ing hypot het ical exam ple, is it likely t o happen in t he real
world?
Th e ca se of oste opor osis
Nat ional I nst it ut e for Clinical Excellence ( NI CE) Technology Appraisal 87 ( NI CE
2005) set s out recom m endat ions for t he use of bisphosphonat es, selective
oest rogen recept or m odulat ors and parat hyroid horm one for t he secondary
prevent ion of ost eoporot ic fragilit y in post m enopausal wom en. The cost effectiveness analysis for this appraisal is com plex wit h alt ernat ive figures
produced for alt ernat ive evidence bases, and pat ient populat ions described in
t erm s of age and bone m ineral densit y. A sum m ary of t he result s are given in
Table 2, which includes a single bisphosphonat e ( as opposed t o t he t hree which
were assessed) , raloxifene, oest rogen, and t eriparat ide.
I n sum m ary, t he guidance recom m ended bisphosphonat es as the preferred
t reat m ent , wit h t he opt ion for using raloxifene if bisphosphonat es were
cont raindicat ed, produced an unsat isfact ory response or if pat ient s were
physically unable t o com ply wit h t he st rict direct ions for t aking bisphosphonat e
m edicat ions ( NI CE 2005) . The use of bisphosphonat es ent ails fast ing and
ingest ion of m edicat ion at least 30 m inut es before breakfast and rem ain st anding
for 30 m inut es aft er t aking t he t ablet .
Ta ble 2 : Cost - e ffe ct iven e ss of t r ea t m e n t s for t h e se con da r y pr e ven t ion
of oste opor ot ic fr a gilit y in post m e n opa usa l w om e n a t 7 0 yea r s of a ge *
Treat m ent
Teriparat ide
Raloxifene
Alendronat e
Oest rogen
Do not hing
*
**
***
Cost
7
3
2
2
1
172
147
818
383
868
QALYs
I ncrem ent al cost effectiveness rat io
relat ive t o DN* *
5.54
5.55
5.56
5.51
5.50
134 728
29 993
16 934
69 585
I ncrem ent al cost effectiveness rat io
relat ive t o next best
opt ion* * *
- 1 257 781
- 24 371
8 934
69 585
Som e t reatm ent s and analyt ic scenarios have been excluded from t he full t able
presented by Stevenson and colleagues ( 2005) for sim plicit y.
Figures taken from report . I CERs based on m odel estim ates, whilst costs and
QALYs are rounded.
Figures calculated from t able, as they are not available from t he report . I CER for
Oest rogen kept t he sam e as in previous colum n for consistency.
The NI CE guidance did not allow pat ient s t he choice of t aking oest rogen, even
t hough it is possible that t hey would consider t he lifest yle rest rict ions associat ed
wit h alendronat e as being disrupt ive t o t he ext ent t hat oest rogen was considered
preferable. I n such a sit uat ion, the pat ient would be offered a t reat m ent t hat
t hey considered t o be worse and m ore expensive ( alendronat e) . Only if they
were “ physically unable” t o follow t he t reat m ent direct ions would t hey be allowed
t o even consider anot her t reat m ent choice ( raloxifene) , and t hen not oest rogen.
Whilst t here are som e added com plexit ies wit h t his t echnology appraisal, due t o
ot her uncert aint ies relat ing t o oest rogen and raloxifene, t he exam ple serves t o
3
highlight t he pot ent ial for cheaper, pat ient - preferred t reat m ent opt ions t o exist in
real life and t o be om it t ed from t reat m ent opt ions by reim bursem ent aut horit ies.
A pa t ie n t - ba se d cost - e ffe ct iven e ss r u le
Clearly, t he current decision rule is capable of producing uncom fort able scenarios
t hat are generat ed by differences bet ween m ean general populat ion values and
individual pat ient values. Som e work has been undert aken t o assess t he
feasibilit y of calculat ing pat ient specific I CERs (Sculpher 1998) . However, t his
approach requires t he elicit at ion of ex ant e healt h st at es from all pat ient s
requiring t reat m ent so as t o calculat e individual expect ed QALYs, which is a
daunt ing prospect .
A part ial resolut ion of t he problem is t o reform ulat e t he current decision rule so
t hat it bet t er reflect s t he key quest ion of ‘which t reat m ent s should be offered t o
t he pat ient ?’. The proposal raised here, is t o allow pat ient s t o have a choice over
t he m ost cost - effect ive t herapy ( as adj udged by m ean general populat ion
values) , those t reat m ent s t hat are less cost ly t han t he cost - effect ive t herapy, and
‘do not hing’. Pat ient s would not be given the choice of t herapies t hat are m ore
expensive and m ore cost ly t han the m ost cost - effect ive t herapy ( for exam ple, ‘C’
in Table 1) .
This reflect s a t wo- part decision process; t he ident ificat ion of t he m ost cost effective therapy using m ean general populat ion values ( i.e. t he current rule) ,
t hen relat ive t o t hat , t he ident ificat ion of t hose t reat m ent s that are cheaper t han
t he m ost cost - effect ive t herapy.
Under t his pat ient - based cost - effect iveness rule, if a pat ient prefers a t reat m ent
such as ‘B’ in Table 1 ( or oest rogen in Table 2) , t hey should be able t o choose it .
I n effect t hey have adjudged that their well- being will be great er under ‘B’ t han
for ‘A’ and t he m ean cost s are lower. I n ot her words, when assessing t he
pat ient - preference I CER, ‘B’ dom inat es. Treat m ent ‘C’ would not be offered even
if t he pat ient chose it , as the increased well- being needs t o be t raded- off wit h
increased cost s.
One furt her issue is wort h considerat ion. I t is possible t hat a form of adverse
select ion could exist , whereby t hose who choose B are expect ed t o have cost s
m uch great er t han the m ean populat ion values (i.e. £20 000) . This would result
in higher pat ient well being but pot ent ially very high cost s. This can be guarded
against by using sub- group analyses t o see if they belong t o a pat ient group who
are expect ed t o have higher cost s that A.
The pat ient based cost - effect iveness rule t hen becom es: you offer t he pat ient t he
choice of the t reat m ent t hat has the highest I CER under the t hreshold, or a lower
cost t reat m ent if and only if t hey belong t o a pat ient sub- group t hat has lower
expect ed cost s t han t he m ost cost - effective opt ion.
4
Pot en t ia l pr oble m s
Two issues are wort h further considerat ion. First ly, t he nat ure of the cost savings
produced by the proposed rule, as t hese are not cert ain. Secondly, t he ‘validit y’
of a rule which offers a pragm at ic solut ion wit h no t heoret ical base.
Nat ure of t he cost savings
The pat ient - based cost - effectiveness rule offers t he possibilit y of pat ient s
choosing a cheaper t reat m ent ( ‘B’) t han t hat recom m ended using t he current
approach ( ‘A’) . However, it is possible that wit hout this choice, som e pat ient s
would have chosen ‘do not hing’. I n such circum st ances, the offer of an
alt ernat ive t reat m ent ( ‘B’) raises the possibilit y of increased cost s. Consequent ly,
whet her t he proposed rule is cost -saving or cost - increasing at t he populat ion
level, is an em pirical quest ion.
Theoret ical validit y of the rule
Whilst t he proposed rule has been described in t he cont ext of cost - effect iveness
decisions, and t aps int o not ions of a pat ient - preference I CER, it does not have t he
t heoret ical base of cost - effectiveness analysis. I t is a pragm at ic solut ion, t hat
m ixes t oget her societ al and pat ient perspectives. I t could also be argued t hat t he
wider choice it provides m oves away from t he not ion of t he public provision of
healt h care, t o a social insurance m odel where pat ient s have a right t o choose
from a m enu of approved t reat m ent s.
So, does t he lack of a t heoret ical foundat ion and t he m ixing up different
perspect ives wit hin a decision rule invalidat e t he rule? I t is clear t hat the NHS
does not operat e a single all-encom passing evaluat ive fram ework. Whilst ext rawelfarism is used by m any healt h econom ist s t o j ust ify t he predom inant
evaluat ive fram ework used by t hem selves, t he NHS uses a range of decision
m aking crit eria from a m ixt ure of sources; t heoret ical, pragm at ic and polit ical.
These different views are recognised by Drum m ond and colleagues ( Drum m ond
et al, 2005) who cont rast t he pragm at ic ‘decision- m aking approach’ wit h t he
t heoret ical approaches of welfarism and ext ra- welfarism . The rule forwarded in
t his paper is clearly pragm at ic, and from a decision- m aking perspect ive, I would
argue that it s desirabilit y can be evaluat ed. The decision m aker needs t o
evaluat e whet her t he benefit s the rule confers in t erm s of great er choice and
great er healt h benefit s as evaluat ed by t he pat ient , are wort h t he pot ent ial ext ra
cost and reduced healt h benefit s as evaluat ed by a populat ion t ariff.
Su m m a r y
Cost - effect iveness rules have developed t o answer a t echnical question, wit hout
due regard for pat ient choice. Am ending t his rule allows great er choice for t he
pat ient wit hout necessarily increasing t he program m e cost . However, using t he
m et ric of general populat ion values this alt ernat ive decision rule reduces healt h
gains. This loss of ex post societ y- valued healt h gain m ust be balanced against
t he increase in pat ient choice and ex ant e pat ient - valued healt h gain. Whet her
societ y is willing t o bear t he pot ent ial ext ra cost for t hese gains becom es the
cent ral quest ion.
I t should be not ed t hat when funding decisions are operat ionalised, healt h care
professionals reint erpret t hem t o allow pat ient choices of this nat ure. I t is also
5
possible t hat such circum st ances are rare, and m ade rarer st ill by t he use of noncost effect iveness inform at ion in the decision process t o account for pat ient
concerns. Consequent ly, the adopt ion of t his pat ient - based cost - effect iveness rule
m ay not alt er m any decisions com pared t o t he current approach. Even if this
were t he case, it would represent a sm all but profound shift in t he way in which
evaluat ions are concept ualised, by recognising the cent ral im port ance of pat ient
values and pat ient choice.
6
Re fer e nces
Brazier J, Akehurst R, Brennan A, Dolan P, Claxton K, McCabe C, Sculpher M,
Tsuchiya A. Should pat ient s have a great er role in valuing healt h st at es? Applied
Healt h Econom ics and Healt h Policy 2005; 4: 210- 208.
Drum m ond MF, Sculpher MJ, Torrance GW, O’Brien BJ, St oddart GL. Met hods for
t he econom ic evaluat ion of healt h care program m es. Third edit ion. Oxford:
Oxford Universit y Press, 2005.
Gold M, Siegel J, Russell L, Weinst ein M. Cost - effect iveness in healt h and
m edicine. New York: Oxford Universit y Press, 1996.
Nat ional I nst it ut e for Clinical Excellence. Bisphosphonat es ( alendronat e,
et idronat e, risedronat e) , select ive oest ogen recept or m odulat ors ( raloxifene) and
parat hyroid horm one ( t eriparat ide) for t he secondary prevent ion of ost eoporot ic
fagilit y fract ures in post m enopausal wom en. London: Nat ional I nst it ut e for
Clinical Excellence, 2005.
Sculpher M. The cost -effect iveness of preference- based t reat m ent allocat ion: t he
case of hyst erect om y versus endom et rial resect ion in t he t reat m ent of
m enorrhagia. Healt h Econom ics 1998; 7: 129- 142.
St ephenson, Lloyd Jones M, De Nigris E, Brewer N, Davis S, Oakley J. A
syst em at ic review and econom ic evaluat ion of alendronat e, et idronat e,
risedronat e, raloxifene and t eriparat ide for t he prevent ion and t reat m ent of
post m enopausal ost eoporosis. Healt h Technology Assessm ent 2005 ; 9( 22) .
Weinst ein MC. Principles of cost - effect ive resource allocat ion in healt h care
organizat ions. I nt ernat ional Journal of Technology Assessm ent in Healt h Care
1990; 6: 93- 105.
Ackn ow le dge m e n t s
The aut hor would like t o t hank Professor John Brazier, Professor Ron Akehurst
and Dr Colin Green for helpful com m ent s, and Dr Mat t St evenson for com ing up
t he ost eoporosis exam ple. However, t he paper m ay not represent their views on
t his issue.
The aut hor is funded by t he Nat ional I nst it ut e for Healt h Research, as part of t he
Trent Research and Developm ent Support Unit .
7