Tackling health inequalities is a key part of the NHS Plan. Historically, your age, gender, ethnicity and deprivation have affected how long you wait for surgery. This inequality has been reduced across England, but data indicates it has not been eradicated.

As part of its Clinically Prioritise and Treat programme, the NHS Institute for Innovation and Improvement expressed concern that historically routine patients were not treated in date order.

For this analysis, source data for waiting times was measured as the time interval from decision to admit to the date the patient was treated.

This differs from the waiting times reported by the Department of Health, which attempts to adjust for times where a patient was unfit. A patient's wait can also start again from zero if they decline a "reasonable" appointment.

Studies show socio-demographic factors affect the waiting times for hip replacement. In fact, they appear to influence waiting times even after the effects of clinical need have been discounted.

The chart below left shows the median waiting time for elective hip replacement patients by the least and most deprived quintile of patients. The times for both groups have dropped since 2001.

In 2001, patients from the most deprived group tended to wait 15 per cent longer than the least deprived group. By 2007, this difference had vanished and both groups waited on average for about the same time.

In 2001, the wait for a hip replacement ranged between 32 weeks for a 55-59 year old and 20 weeks for someone over 90 years old. However, in 2007, the median waiting time was 17 weeks, irrespective of age. A similar effect can be seen for gender - males wait slightly longer - in 2001 but this effect had vanished by 2007. Waiting times by ethnicity also follow a similar pattern.

Working the system

The ratio of median waiting times for the most deprived and least deprived quintiles of patients for English acute trusts is shown in the chart below right. A ratio of 1 indicates that both groups have the same waiting time. High ratio values indicate that waiting times are longer for the "most deprived" group. Only trusts with large volumes and postcode allocation of sufficient quality have been included.

While most trusts have around equal waiting times for both groups, in one trust the most deprived patients appear to wait twice as long as those from the least deprived group. Even routine patients may differ in the urgency of their operation and variable waiting times in the past may be explained by consultants being able to prioritise cases. Tighter waiting-list targets may have made this more difficult.

More deprived patients are more likely to be categorised as "did not attend" for outpatient appointments. There are tales of better-off patients being more able to "work the system" and get treated sooner.

Overall, the reduction in waiting-time variation suggests that the prioritise and treat programme (and its earlier incarnations) has encouraged trusts to treat routine patients in date order. Factors such as age, gender, ethnic group and deprivation are now less likely to influence how long patients wait.

It is likely that the reduction in variation by socio-economic group is more to do with a general tightening up of waiting-list processes rather than action to reduce discrimination. It is important for commissioners and providers to closely monitor their waiting lists to ensure they are not indirectly discriminating on the grounds of socio-demographic factors.