NZ Hospital Performance (2001-09) Outputs, Inputs, and Productivity - - PowerPoint PPT Presentation
NZ Hospital Performance (2001-09) Outputs, Inputs, and Productivity - - PowerPoint PPT Presentation
NZ Hospital Performance (2001-09) Outputs, Inputs, and Productivity Motivating questions Have NZ hospitals become more/less productive in the past 9 years (2001-09)? What is the evidence? What are the limitations in drawing inferences
Motivating questions
Have NZ hospitals become more/less productive in the
past 9 years (2001-09)?
What is the evidence? What are the limitations in drawing inferences from available data
and statistical models?
Are there identifiable differences in hospital
productivity across DHBs?
What is the evidence? What factors explain differences? What are the limitations in drawing inferences from available data
and statistical models?
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Hospital Outputs
Data
NMDS 2001-2009
all facilities, all discharges
Measures
Case mix weighted total discharges per month/year
using relative resource use by DRG (WEIS) as weights
Average length of stay Proportion of day stays
Shortcoming
No outpatient & emergency department visits
~25% (or more) of total hospital output
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Hospital Output – over the years
700000 750000 800000 850000 900000 950000 1000000
- No. of discharges
2.8 2.9 3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 2001 20022003200420052006200720082009
Average length of stay (days)
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23% increase 16% decline Year Year
- No. of Discharges
Ave Length of Stay
Total Discharges per month
2500 2700 2900 3100 3300 3500 3700 3900 4100
Mean discharges per month
2500 2700 2900 3100 3300 3500 3700 3900 4100
Mean WEIS-weighted discharges per month
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- No. of Discharges
WIES weighted No. of Discharges
Time (2001 – 2009) Time (2001 – 2009)
Average length of stay & proportion day stays
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50 60 70 80 90 100 110 120 80 100 120 140 160 180 200
Year Year
Change in Average Length of Stay Change in Proportion of Day Stays Index (2001=100) Index (2001=100)
Change in WEIS-weighted Annual discharges
80 90 100 110 120 130 140 150 2001 2002 2003 2004 2005 2006 2007 2008 2009
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Year
Index (2001=100)
Hospital Inputs
Data
DHB Provider expenditures 2001-2009 (MoH)
By month, disaggregated by type, with FTEs
Measures
Total real expenditures in 2001 NZD (1st Qtr) Deflation using GDP deflator (Stats NZ) Proportions by type of expenditure (later)
Shortcoming
DHB-level aggregation No breakdown by inpatient, outpatient, ED
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DHB provider expenditure over the years
$3.5 $4.0 $4.5 $5.0 $5.5 $6.0 $ billions
Total DHB (real) expenditure
1.0000 1.0500 1.1000 1.1500 1.2000 1.2500 1.3000 1.3500 1.4000
DHB (real) expenditure per capita
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40% increase 26% increase Year Year
$thousands
DHB Expenditure breakdown
Personnel 60% Outsource d Services 7% Clinical Supplies 14%
Infrastructu re & Nonclinical supplies 19%
Input Expenditure shares
Medical 25% Nursing 39% Allied Health 16% Support 3% Manageme nt 17%
Personnel Expenditure shares
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DHB Expenditure variation
90 100 110 120 130 140 150 160 170 180 190
01 02 03 04 05 06 07 08 09
Total Real Expenditures
90 100 110 120 130 140 150 160 170 180 190
01 02 03 04 05 06 07 08 09
Real Expenditure per discharge
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Year Year
Index (2001=100) Index (2001=100)
Productivity
Measure: Output per $ of (input) expenditure
NMDS Outputs = inpatient stays (case mix weighted)
incl. day stays counted as 0.5 days Excl. outpatient & ED visits
DHB provider expenditures in 2001 NZD(MoH)
Deflated by GDP deflator (StatsNZ)
Results
12% decline between 2001 & 2009
BUT measure is based on inpatient stays so underestimates
productivity
IF share of outpatient and ED increased over time then decline is
- ver-stated DID SHARE increase by >12%?
Substantial variation across DHBs
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Change in Productivity over time
60 65 70 75 80 85 90 95 100 105 110 2001 2002 2003 2004 2005 2006 2007 2008 2009
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Year
Index (2001=100)
Modelling variation in productivity
Data: Panel of monthly data on case-mix weighted hospital output
(partial) and DHB provider expenditure for 9 years
Super-population perspective for statistical inference Hospital productivity of DHB at time t is a function of …
time-varying DHB characteristics (eg. case mix, organization, resource allocation)
time-invariant DHB characteristics (eg. Population size and demographic composition, location)
time-varying DHB-invariant characteristics (policy directive)
Some characteristics observed, some not Dynamic (changing) relationships – with past characteristics (including
productivity itself)
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Productivity variation: Regression models
Static Models
Specifications estimated (so far)
Pooled with robust standard errors for DHB clustering Random effects Fixed effects
Dynamic Models
Lagged dependent variables Endogenous regressors (input expenditures, acute admissions,
etc)
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Model-based estimates of temporal variation in productivity
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- 0.01
- 0.005
0.005 0.01 0.015 0.02 0.025 Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Seasonal Variation (Base=Jan)
- 0.06
- 0.05
- 0.04
- 0.03
- 0.02
- 0.01
02 03 04 05 06 07 08
Annual Variation (Base=2001)
Monthly Data Yearly Data
Year Month
Percentage Change (Base=2001) Percentage Change (Base=Jan)
Other (preliminary) results
Static models
Monthly data
DHB fixed effects specification best Significant effects: Proportion Pacific (-ve), Proportion newborn (-ve),
proportion arranged admissions (+ve), and significant month & year variation (previous slide)
Annual data
DHB random effects specification best Only year dummies significant (previous slide)
Dynamic models (so far only with annual data)
Serial correlation in errors so dynamic model more efficient Significant effects:
Lagged productivity (+ve): higher past productivity -> higher current Economies of scale (+ve): larger admission volume -> higher productivity
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Quality of hospital services
Composite measure (annual) based on patient safety
indicators
based on 11 (of 20) provider-level patient safety indicators (PSIs) developed by AHRQ
Construction of measure
1.
Risk-Adjustment (for each component)
Patient-level Logistic regressions for each PSI to derive predicted values of the outcomes of interest on full nine years of data in NMDS.
2.
Reliability Adjustment (for each component)
Need to adjust indicator for reliability by isolating true variability of indicator.
3.
Combining 11 components (multi-dimensionality)
Need weighting system to combine indicators of different dimensions into a single composite index.
Equal Weights, Factor Analysis based weights, Expert opinion based weights
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Change in Hospital Quality
80 90 100 110 120 130 140 150 2001 2002 2003 2004 2005 2006 2007 2008 2009
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Year
Index (2001=100)
Increase in index => decline in quality
Model-based results for hospital quality
Findings from preliminary panel econometric
regressions
Total DHB expenditures have little explanatory power
Source: Bowden-Desai paper presented at NZAE (2011) 20
Significant Effects Sign Time +ve Proportion Female +ve Proportion NZ European
- ve
Proportion Pacific
- ve
Clinical Severity +ve
Ongoing work and next steps
1.
Further refinement of dynamic models for Productivity, Input expenditures, Quality ……to analyze relationships between these 3 variables in a dynamic model setting
2.
Examination of effects of DHB monitoring (MoH data) and changes in hospital output composition (DHB data)
3.
Further refinement of hospital (patient safety) quality index using (ongoing) survey data on ranking of PSI by clinicians
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