The effect of social deprivation on hip fracture incidence has not changed

over 10 years in England Arti Bhimjiyani1, Jenny Neuburger2, Yoav Ben-Shlomo3, Celia Gregson1

1Musculoskeletal Research Unit, University of Bristol2London School of Hygiene and Tropical Medicine, Nuffield Trust London

3School of Social and Community Medicine, University of Bristol

No conflicts of interest to disclose

Background

• England & Wales: ~65,000 hip fractures per year1

• UK annual hospital costs of incident hip fracture ~£1.1 billion2

• Worsening levels of deprivation are associated with:• Higher rates of hip fracture3

• Poorer outcomes post-hip fracture4

• Secular trends show an increase in hip fracture incidence for men and plateau for women in the UK5

• Unclear how the association between deprivation and incident hip fracture has changed over the last decade

1 National Hip Fracture Database annual report 2015. London: RCP, 2015 4 Thorne K et al. Ost Int. 2016;27(9):2727-372 Leal J et al. Ost Int. 2016 Feb;27(2):549-58 5 van der Velde et al. Ost Int. 2016;27(11):3197-3206 3 Quah C et al. JBone Joint SurgBr. 2011;93(6):801-5

Hypothesis & Aims

Hypothesis • Secular changes in hip fracture incidence have not occurred equally

across all levels of deprivation i.e. any declines in incidence are likely to be seen predominantly in less deprived people

Aims• To determine the association between deprivation and hip fracture

incidence, by gender

• To examine if secular trends in hip fracture incidence over 10 years differ by deprivation and gender

Hypothesis & Aims

Hypothesis • Secular changes in hip fracture incidence have not occurred equally

across all levels of deprivation i.e. any declines in incidence are likely to be seen predominantly in less deprived people

Aims• To determine the association between deprivation and hip fracture

incidence, by gender

• To examine if secular trends in hip fracture incidence over 10 years differ by deprivation and gender

Data source: Hospital Episode Statistics (HES)

• Anonymised, patient-level data extract from the HES Admitted Patient Care database

• Routinely collected data from all English NHS hospitals

• Time period: April 2001 to March 2012

• Study Population • Male and female English residents aged ≥50 years • Patients admitted with an index hip fracture (i.e. 1st hip

fracture), or in-hospital index hip fractures

HES Exposure: Index of Multiple Deprivation (IMD) 2010

• Based on a classification of 32,482 local areas defined by an individual’s postcode

• 7 domains:1. Education, skills & training 5. Crime2. Barriers to housing & services 6. Income3. Health & disability 7.Employment 4. Living environment

• Quintiles-based ranking of IMD scores:Q1 – Least deprived . . .Q5 – Most deprived Source: Index of Multiple Deprivation 2010

Neighbourhood Statistics Release

HES Outcome: Hip Fracture

ICD-10 disease codes:• S72.0 (Fracture of Neck of Femur)• S72.1 (Pertrochanteric fracture)• S72.2 (Subtrochanteric fracture)

HES Outcome: Hip Fracture

ICD-10 disease codes:• S72.0 (Fracture of Neck of Femur)• S72.1 (Pertrochanteric fracture)• S72.2 (Subtrochanteric fracture)

Mid-year population estimates for England

• Years 2001 to 2012

• Stratified by: Age in 5-year intervalsGenderIMD 2015 quintile

Population Denominator: Office for National Statistics (ONS)

Statistical Analyses

• Annual incidence rates of hip fracture per 100,000 population:Number of index hip fractures x 100,000 by each strata of gender Population count & IMD per year

• Age-standardised (direct) hip fracture incidence rates for males and females stratified by IMD quintiles (reference year: 2001)

• Poisson regression modelling of the association between IMD & hip fracture incidence

• Incident rate ratios (IRRs) (95% confidence interval), adjusted for age, stratified by IMD quintiles & gender

• Reference cat. least deprived quintile (Q1) • Formal tests for interaction

Total Hip Fracture Population: 2001 to 2011

N (%)

No. of patients with hip fracture 577,767Female (%) 433,983 (75)IMD Quintile 1 (Least deprived) 109,265 (18.9) Q2 120,566 (20.9) Q3 122,751 (21.3) Q4 115,080 (19.9) Quintile 5 (Most deprived) 110,105 (19.1)Age (years) mean (SD) 81.6 (9.4)

Q1 Q2 Q3 Q4 Q50.9

1

1.1

1.2

1.3

1.4

Inci

dent

Rat

e Ra

tios (

IRRs

)

Males

Greater deprivation associated with higher incidence in men but less marked for women

Poisson regression modelling adjusted for age Formal test for gender x deprivation interaction (adjusted for age) p<0.001

Q1 Q2 Q3 Q4 Q50.9

1

1.1

1.2

1.3

1.4

Inci

dent

Rat

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tios (

IRRs

)

Females

010

020

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050

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Age

-sta

ndar

dise

d in

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rate

s pe

r 100

,000

2001 2003 2005 2007 2009 2011Year

Female age-standardised incidence is declining over time whilst rates have slightly increased for men

Females

Males

95% CIs have not been shown as very narrow

Time x gender interaction (adjusted for age) p<0.001

Annual % increase: 0.81%

Annual % decline: 1.18%

Age-Standardised Incidence Rates by IMD Quintiles for MEN

No evidence of time x deprivation interaction (adjusted for age) p=0.61

050

100

150

200

250

300

Age

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2001 2003 2005 2007 2009 2011Year

Q5

Q1

Deprivation Annual % change

Q1 +0.90...

Q5 +0.78

010

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Age

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s pe

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2001 2003 2005 2007 2009 2011Year

Age-Standardised Incidence Rates by IMD Quintiles for WOMEN

Time x deprivation interaction (adjusted for age) p<0.001

Q5

Q1

Deprivation Annual % change

Q1 -1.42...

Q5 -0.89

Limitations

• We used an area-based measure of deprivation as a proxy for individual deprivation

• Quality of HES coding may have changed over time

• We lack co-morbidity data

• Our results are derived from English data only

Conclusions

• Deprivation is a stronger predictor of adult hip fracture incidence in men than women

• Hip fracture incidence has declined in women and increased in men across all strata of deprivation from 2001-2011

• There has been no narrowing of the gap between levels of deprivation for men, with some widening of the gap for women, despite national efforts to reduce hip fracture incidence

• Our findings have implications for equity of access to fracture prevention programs nationally

Acknowledgements

Co-authorsCelia Gregson, Jenny Neuburger & Yoav Ben-Shlomo

Funders

Timothy Jones (University of Bristol)

Matthew Hurley (ONS)