Assessment and Appraisal:Fundamental Aspects of Health Care

Kent Woods

Director, NHS Health Technology Assessment Programme

Key themes in health care

• The accelerating pace of health technology

• The interplay of science and judgement at all levels of health care

• The need for rigour in decision-making

• Diagnostic technologiesRadio immunoassay

Flexible endoscopy

Computerised tomography

Diagnostic ultrasound

• Therapeutic technologies1,106 new drugs marketed 1970-92

New devices (pacemakers, stents…..)

New surgical procedures (transplantation, laparoscopy…)

Prescriptions for prevention and treatment of all circulatory diseases, 1981-2000, England

0

20

40

60

80

100

120

140

1980 1985 1990 1995 2000 2005

Year

Pre

sc

rip

tio

ns

(m

illi

on

s)

Drugs

Trial publications and prescriptions for lipid lowering drugs

0

2,000

4,000

6,000

8,000

10,000

12,000

1980 1985 1990 1995 2000 2005

Year

Pre

scri

pti

on

s (t

ho

usa

nd

s)

4S

CARE

WOSCOPS

(statins £308m)

Coronary revascularisation procedures, UK

0

5,000

10,000

15,000

20,000

25,000

30,000

1980 1985 1990 1995 2000 2005

Year

Pro

ce

du

res

Percutaneous coronary intervention Coronary

artery bypass grafting

What is HTA for?

• To supply the evidence base for those who plan, manage, provide or use health services in making decisions

• HTA does not make or determine the decisions

• HTA is needed at every level of health care

• Assessment is a research activity and produces generalisable new knowledge

• ‘Appraisal’ applies that knowledge to specific local circumstances:– Applicability– Social values– Local priorities– Local resources

Responding to the challenge of new technologies

•Clarity (and accountability) of function

•Application of the right skills and competencies

•Assessments are transferable and replicable

Why Separate Assessment and Appraisal?

HTA Programme

NICE

National Screening Committee

NSCAG

National:

[Local commissioning]

[Clinician/patient]

Assessment

Appraisal

A methodology of appraisal

The principles underlying decision-making have received less rigorous attention than the science, e.g:

• Equity?

• Priority?

• Efficiency?

• Individual preference/societal values?

HTA in Support of Appraisal

• NICE– 40-50 TARs per year

• NSC– Systematic reviews on screening for prostate

cancer, Down’s, HPV in cervical screening– RCTs on same topics

• NSCAG– ECMO trial; ventricular assist devices

1. Science informs, but does not dictate, decisions in health care

2. The scientific challenges are:– Synthesising evidence validly– Quantifying uncertainty– Communicating probabilities to those making

decisions

PubMed

0

10

20

30

40

50

60

1980 1985 1990 1995 2000 2005

Year

Pu

blic

ati

on

s/1

00

,00

0/y

r

Adjusted Bayes*

Adjusted health economic*

Future issues for better decision-making

• Assessment– Synthesis from diverse study designs– Preserving transparency– Growing the research capacity

• Appraisal– Adapting to rapidly moving evidence– Developing and ‘selling’ explicit principles– Locating decisions at the right level