Modos de Operación de la CT

These are, of course, matters of considerable interest to the people who hold the budgets in the NHS: the commissioners. The decisions made every day by PCTs in commissioning health care for their communities result in a particular allocation of resources and a corresponding aggregate improvement in, and distribution of, health. But, unless health is measured in some way, PCTs will not know what outcomes result from a given set of commissioned services – and whether commissioning a different set of services would be better overall.

PROMs have a potentially very important role to play in helping PCTs make sure they are getting good value-for-money. The current Department of Health PROMs programme in the NHS in England includes, as noted earlier, both condition-specific and generic measures. The generic instrument being used – the EQ-5D – has two features that make it particularly useful in the context of commissioning.

First, because it describes health in a general way, it facilitates comparisons of health improvements across dissimilar illnesses and treatments. This is critical to assessments of value-for-money, because weighing up benefits and costs necessarily involves assessing health improvements in one area of health care versus deterioration in health elsewhere. Second, the EQ-5D is designed to facilitate economic evaluations, and is accompanied by social ‘value sets’ (Dolan 1997) that make straightforward the estimation of QALYs from EQ-5D data. The EQ-5D is already widely used in cost-effectiveness analysis in the United Kingdom – indeed, it is the instrument recommended for use in evidence submitted to NICE (National Institute for Health and Clinical Excellence 2008a).

A simple explanation of how EQ-5D health states are valued and used in the estimation of QALYs is given in the box opposite.

At present the PROMs data are available only to the NHS in England for a small set of elective surgical procedures. But if the collection of PROMs data is rolled out across more conditions (see Insight box on p 5) and are embedded in most health service delivery, it will be possible to analyse these data at a number of levels. For example:

n PROMs data could be examined alongside programme budgeting data to look for high-level disparities in the value yielded from PCT allocations of resources between programme budgets

n it would be possible to examine how levels of spending relate to health outcomes for patients in each programme budget area

n the analysis can also drill down to look at the value-for-money of particular services n alternatively, drilling down still further, it would be possible to investigate differences

in the effects of treatment on different patient sub-groups, and the comparative effectiveness of different ways of delivering services.

There are, however, some important limitations to using EQ-5D data from the PROMs programme in this way. In particular, there are challenges in applying the standard methods of economic evaluation to PROMs data because they are observational

Valuing EQ-5D PROMs data

As explained earlier (see ‘A Primer on PROMs’), the EQ-5D is a generic measure of health-related quality of life. For the purposes of economic evaluation, standard methods of analysis typically rely on data from the first part of the instrument, where patients tick boxes to describe their health in terms of the dimensions and levels on the EQ-5D. For example, a patient may describe their health as follows:

No problem on a dimension is coded as ‘1’, some problems as ‘2’ and extreme problems

as ‘3’. Recording these in the order the dimensions appear, this health state is ‘12331’ – this is simply a shorthand way of describing this particular state. The standard 3-level version of the EQ-5D describes (35 _{=) 243 possible health states, from 11111} (full health) to 33333 (extreme problems on each dimension).

To use these data in the estimation of QALYs, a quality of life ‘weight’ for each of the 243 states is needed. These weights (also referred to as utilities or values) are meant to reflect the opinions of the general public about what it would be like living with these health problems. A UK social value set is available for all 243 states, obtained from responses to questions asked of a large, representative sample of the general public (Dolan 1997; Szende et al 2007). These are the values used by NICE in assessing cost-effectiveness.

continued overleaf

By placing a tick in one box in each group, please indicate which statement best describes your health today.

Mobility

I have no problems in walking about I have some problems in walking about I am confined to bed

Self-care

I have no problems with self-care I have some problems with self-care I am unable to wash or dress myself

Usual activities

I have no problems with performing my usual activities I have some problems with performing my usual activities I am unable to perform my usual activities

Pain/discomfort

I have no pain or discomfort I have moderate pain or discomfort I have extreme pain or discomfort

Anxiety/depression

I am not anxious or depressed I am moderately anxious or depressed I am extremely anxious or depressed

Limitations and problems with using PROMs data in