Primary care supply

Access to primary care is a foundation stone of health care quality, and makes a crucial contribution both to patient experience and improvement in population health outcomes. There is evidence that improved access to primary care can help to prevent illness, manage

chronic conditions more effectively and reduced unnecessary utilisation of secondary care59,

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; though evidence on the impact of marginal changes in primary care supply on mortality in high income countries is mixed61, 62,59. We use a simple and objective measure of access to primary care: the number of patients per primary care physician. Measures of patients’ subjective experiences of primary care access are also available, based on the annual National GP Patient survey. However, this survey only goes back to 2006/7 and has a response rate of around 30% which varies substantially between practices and so may hamper comparisons in social gradients between sub-national areas.

Previous studies in high income countries, including the UK, have found significant geographical variations in the distribution of primary care physicians.63646566676869 Data from England between 1974 and 2006 showed substantial and persistent geographical inequalities in supply of general practitioners (GPs) relative to need between NHS administrative areas.707172 However, these studies focused on large areas which made it difficult to accurately pinpoint primary care shortages in specific disadvantaged

neighbourhoods.

Our indicator of primary care supply evaluates socioeconomic inequality in GP supply between small area populations from 2004/5 to 2013/14. We use LSOA level data which allows us to capture changing patterns of socioeconomic inequality in much more fine- grained detail than previous studies. We define GP supply as the number of patients per full time equivalent GP, excluding registrars and retainers, adjusted for age, sex and

neighbourhood ill-health using the Carr-Hill workload adjustment (see Appendix 1 for details). The numerator is the total number of people alive at mid-point in the current

financial year while the denominator is the number of FTE GPs attributed to each small area in the current indicator year. Further technical details of how this index was computed are presented in Appendix 1.

Figure 13 National social gradient in patients per GP in 2011/12 – adjusted

Notes:

i. Dots represent decile groups. The inverted U shape pattern indicates that

neighbourhoods in the middle of the socioeconomic spectrum have less primary care supply than the most and least deprived neighbourhoods, after adjusting for

differences in need.

ii. The slope of the line is the slope index of inequality. In this case, the slope is negative showing “pro-poor” inequality in patients per GP favouring deprived areas. iii. The shaded area shows the “inequity gap”. In this case, this gap is negative indicating

that bringing all neighbourhoods to the level of the least deprived would require losing some GPs in deprived neighbourhoods.

Figure 14 Caterpillar plot of the absolute gradient index of inequality in patients per GP in 2011/12 at CCG level

Notes:

i. CCGs are ranked from least equitable (left) to most equitable (right).

ii. The dotted horizontal line shows the national average. CCGs to the left with confidence intervals above this line have worse than average equity performance, and vice versa. iii. In this unusual case, there are many negative SSIs (at face value indicating “pro-poor”

inequality) as well as positive SIIs indicating “pro-rich” inequality. However, since we under-estimate need in deprived neighbourhoods, as explained in Chapters 4 and 6 and Appendix 1, we do not interpret negative SIIs as representing “pro-poor” inequality but rather as indicating no measurable “pro-rich” inequality.

Figure 15 Scatter plots of CCG performance on patients per GP in 2011/12 against deprivation, showing both mean performance and equity performance (absolute gradient index)

Unadjusted trends show that there has been a significant divergence in GP supply between the most deprived fifth of areas and the other areas in the country from 2006/07 onwards. Since 2006/07 the most deprived fifth of areas experienced a sustained trend of increasing GP supply (decreasing numbers of patients per GP) whilst GP supply in all the other areas

decreased over time. We prefer the need adjusted findings, however, because in cross section the unadjusted findings come up with the potentially misleading message that people living in deprived neighbourhoods have substantially more GP supply than others. This is a

potentially misleading finding, because it fails to allow for the fact that deprived

neighbourhoods tend to suffer more ill health than affluent neighbourhoods, and so have greater healthcare needs.

Adjusting these results for need using the Carr-Hill workload adjustment changes the levels of these lines, but we see a similar equity trend. We see a sustained reduction in both absolute and relative inequality as measured by the SII and RII over the period, and by 2010/11 need

adjusted GP supply actually becomes pro-poor. This is also evident in the social gradient graph for 2011/12, where we see the lowest numbers of patients per GP in the most deprived areas and a negative inequity gap. The caterpillar plot shows that there are substantial

numbers of areas significantly more and less equal than the mean. The correlation plot shows that by 2011/12 there is little evidence of a social gradient between CCGs: there is no

association between mean patients per GP and deprivation at CCG level. By contrast, there is some evidence that more deprived CCGs do better at reducing deprivation-related inequality in GP supply within their own patch: there is a clear though weak negative association between equity in patients per GP (absolute gradient index) and deprivation at CCG level.