Title: Models of care for the delivery of secondary fracture prevention after hip fracture: a health service cost clinical outcomes and cost-effectiveness study within one Region
Funder: Department of Health (England)

Abstract: CONCEPTUAL FRAMEWORK: Natural Experimental Study to evaluate unplanned variation in secondary fracture prevention after hip fracture across hospitals in the South Central region to analyse their impact on costs and health outcomes and determine the cost-effectiveness of the different models of careTEAM EXPERTISE: The team undertaking this research include health professionals involved in the care of hip fracture patients (e.g. rheumatologist primary care physician orthogeriatrician) senior academics (biostatistician health economist qualitative methodologist) NHS managers and patient representativesRESEARCH QUESTIONS:1) Characterise the way hospitals in the South Central region have provided secondary fracture prevention services for hip fracture patients over the past decade2) Identify the reasons why hospitals chose their specific model of service delivery and assess barriers to change3) Establish the cost-effectiveness of different hospital models for delivery of secondary fracture prevention and provide a set of life-time health cost-profiles for patients with hip fractures4) Evaluate the impact changes to the delivery of secondary fracture prevention have had on health outcomes by altering trends in hip re-fracture rates NHS costs and life expectancyOUTCOMES: Second hip fracture (primary outcome); NHS costs (quality-adjusted) life expectancy non-hip fragility fractures (secondary outcomes)CONFOUNDERS: Adjustment for case-mix including variables age gender area deprivation Charlson co-morbidity indexSTUDY SAMPLE: English national Hospital Episode Statistics (HES) data linked to national mortality data from 1999 to 2011 for the South Central region. A cohort of hip fracture patients (4260 patients per year in South Central) will be identified through OPCS4 operation codes and ICD diagnostic codes. The hospital provider code will allow identification of the 11 hospitals in the region. A cohort of hip fracture patients from the UK General Practice Research Database (GPRD) from 1999 to 2011 identified using READ/OXMIS codes.CHARACTERISATION: Hospitals in the South Central region will be characterised according to the way they currently deliver secondary fracture prevention services and changes made to service delivery over the past decade. Characteristics and their date of implementation include: Integration of falls and osteoporosis services across primary and secondary care Orthogeriatricians Fracture liaison Nurses Falls Nurses DXA scanners Rehabilitation on acute ward or Geriatric Orthopaedic Rehabilitation Unit Publication of national guidance (BOA Blue Book SIGN NICE).QUALITATIVE RESEARCH: We will seek to understand the reasons why hospitals in the region adopted their current diverse models for delivery of secondary fracture prevention and identify barriers to changes in service delivery. We will conduct qualitative one-to-one interviews with Health professionals who specialise in Osteoporosis services and NHS managers. The interviewer will use a structured ‘topic guide’. Interviews will be audio-recorded anonymised transcribed then analysed thematically.HEALTH ECONOMICS: Data from HES and GPRD will be used to estimate the hospital and non-hospital costs associated with hip fracture (first and subsequent). A Markov model will simulate the costs and health-related quality of life (QoL) associated with the different hospital models of secondary fracture prevention. A cost-effectiveness and cost-utility analysis will be performed using outcome measures such as prevention of hip fractures life expectancy and Quality-Adjusted Life Years (QALYs) gained. The Markov health states (e.g. primary hip fracture hip re-fracture death discharge destination (home or care home)) will reflect the natural history of hip fractures and the impact of the different models of care. Transition probabilities will be informed by HES and mortality linked data and relate to a particular model of care. Relative effectiveness measures will be applied to the transition probabilities to model the impact of the different models of care. Costs and QoL values will be assigned to each health state. NHS resource use associated with the treatment pathway of hip fracture patients will be identified and valued using appropriate data sources. QoL data will be derived from a literature search. Incremental cost-effectiveness ratios (ICERs) will be estimated for the different models of care and depicted on the cost-effectiveness plane. Probabilistic sensitivity analysis will be used to propagate parameter uncertainty and capture decision uncertainty by using cost-effectiveness acceptability curves and reporting credible intervals around the ICERs.STATISTICAL ANALYSIS: The hospital will be the unit of analysis and the exposure of interest is the time the hospital changed delivery of care (e.g. use of orthogeriatrician Fracture Liaison Nurse) between 1999 and 2011. Interrupted time series analysis will be used to evaluate the impact of change in service delivery on trends in rates of second hip fracture and mortality adjusting for socioeconomic status and case-mix. Segmented linear regression models are used to estimate the monthly proportions of re-fractures and deaths. Controlling for baseline level and trend the models estimate changes in levels and trends of rates after the change in service delivery. For each time series model we will include an extensive preintervention period to control for biases in level and trend at baseline. Separate models will be fitted for each hospital.RESEARCH OUTPUTS: Engage with key stakeholders including NHS managers Healthcare professionals patients and the public for interpretation dissemination and direct communication of the main findings. This will be facilitated through involvement of an NHS manager as a co-applicant collaboration with the FRISCY network and PPI representation. Findings will be fed back to stakeholders at individual hospitals published in peer-reviewed journals and at national conferences.


Research activity codes: 8.1 ORGANISATION AND DELIVERY OF SERVICES;7.3 MANAGEMENT AND DECISION MAKING
Health categories: MUSCULOSKELETAL