Title: Utilizing MultiVari and ANOVA for Billing
1Utilizing Multi-Vari and ANOVA for Billing
Charge Capture Projects in a Healthcare Setting
- Mike ONeill
- Lean Six Sigma and
- Business Improvement in Healthcare Summit
- March 17, 2009
2Agenda
- Multi Variance Analysis benefits and approach
- Analysis of Variance (ANOVA)
Hypothesis testing overview - Hypothesis Tests - Healthcare insurance denial
type - Billing Charge capture case studies
- Insurance Claim Denials Reduction
- Hospice Billing Charge Capture
- Intravenous (IV) Solutions Charge Capture
3Gundersen Lutheran Health System
- Integrated Delivery System
- Over 6,000 Employees
- 325 bed Tertiary Medical Center
- Level II Regional Trauma Center
- Nationally Recognized
- Top 100 Designations
- Cancer Care
- Cardiac Care
- Health Grades Distinguished Hospital
- Western Clinical Campus for UW-Madison Medical
School and School of Nursing - Medical Foundation
- Clinical Research Program
- Residency Medical Education Programs (1,199
Students) - Variety of affiliate organizations including
rural hospitals, nursing homes, etc. - 400 physician multi-specialty group practice
- Employed physician model
4Benefits of Multi-variance Analysis
- To look at process stability over time
- To determine with high statistical confidence the
capability of the outputs of a process - To identify what is causing variation in the
process - To obtain initial components of variability.
Different Insurance Carriers Departments
Physicians - To provide direction and input for Improvement
activities
5Initial Approach
Want to understand stability and capability of
the Y - output(s)
6Insurance Claim denials
f (Claim Types, Carriers, Depts, Physicians,
Procedure Types, ...)
Y
y1, y2, y3, y4
Weekly Denials
.With plenty of xs / drill downs
Find clues of key drivers Practically Graphically
Statistically
7Know what key Xs to Analyze(Initial filtering
from Process Mapping)
- With multiple xs that may lead to high
variability want - to focus on the noise/uncontrolled type variables
first - Process variation due to
- Similar type variables
- Insurance Carriers
- Departments
- Physicians
- Billing/Coding Staff
- Differences in variables over time
- Week to Week
- Month to Month
- Quarter to Quarter
Discrete variables
Continuous variables
8Another look at Noise Variables
- For Discrete Input Variables
- Test for Variability within a piece
- Example Four procedures per patient visit
- Test for Variability within a batch
- Example Variability across procedures by
physician - Test for Variability across batches
- Example Variability across procedures within a
month - For Continuous Input Variables
- Test for Variability within a time span
- Example Ten insurance coverage records per day
- Test for Variability across short time spans
- Example Variability across week
- Test for Variability across longer time times
- Example Variability across months, quarters or
longer
9A Multi Vari Approach
- Determine if the variables are continuous or
discrete - Gather data and study key inputs impacting output
(X vs. Y) - Look at the Xs and consider which are causing
variability in the process output - Go back and look at Xs again missing any key
inputs to study? - Look for curves, groupings and patterns in
continuous data sets - Can use the same approach whether output (Y) is
continuous or discrete - Choose and apply appropriate analysis tool
10A Multi Vari Approach (cont)
- Study controlled and uncontrolled (noise) inputs
but.. - Focus on uncontrolled inputs first
- Variation in the Noise variables can produce
dramatic mean shifts and changes in variability
that lead to process instability - These sources of variation must be attacked first
before leveraging the important controlled input
variables in a systematic way - Identify similar processes and study variability
differences - Insurance Carrier to Insurance Carrier
- Clinic Department to Clinic Department
- Location to Location (Wisconsin, Minnesota, Iowa)
- Coder to Coder Insurance follow up to Insurance
follow up staffer - Differences in process variation over time
- Week to Week
- Month to Month
Complete Multi-Vari studies to identify potential
key inputs
Review Data andPrioritize Key Input Variables
11Multi vari charts can be used to investigate
relationships among variables
- Discrete Variables
- Boxplots
- Interval Plots
- Main Effects Plots
- Interaction Plots
- T-tests comparing two groups
- ANOVAs
- Continuous Variables
- Scatterplots
- Correlation
- Regression
- Multiple Regression
We will review how some of these tools were used
for three projects within Gundersen Lutheran
Health System. Involving discrete input
variables.
12Analysis of Variance (ANOVA) and Hypothesis
Testing
13Analysis of Variance Studies (ANOVA)
- Anova studies used to perform statistical tests
for comparing - Means
- Medians
- Variances
- Performed to answer your hypothesis (Are
Insurance Claim denials marked patient
responsibility always true?) - Assumption All PR (patient responsibility)
denial codes generated by Insurance
Carrier requires no investigation
and can be transferred directly to
patient - Null Hypothesis PR denials are the same
- Alternative Hypothesis PR denials are not the
same - The statistical test will generate a probability
(p) value for your hypothesis which is based on
the assumption there is no difference. - Guideline If P value lt .05 this indicates there
is a difference - We will look at how a study was performed for the
- above scenario but lets review Hypothesis
testing further
For Discrete inputs (x) Continuous outputs (y)
14Hypothesis Testing Concepts Enable
You To .
- Properly handle uncertainty
- Minimize subjectivity
- Question assumptions
- Prevent the omission of important information
- Manage the risk of decision errors
15Key Terms
Ho Null Hypothesis Ha Alternative
Hypothesis P Value Probability Value
16Hypothesis Testing What is it
for Statisticians ?
17Hypothesis Testing What is it
for the Average Person ?
Ho Coding doesnt matter for insurance claim
reimbursement Ha Coding does matter for
insurance claim reimbursement Ho Procedure X
Avg. Cycle Time Procedure Y Avg. Cycle Time Ha
Procedure X Avg. Cycle Time Procedure Y Avg.
Cycle Time For one of your projects Ho What
is the Null Hypothosis? Ha What is the
Alternative Hypothesis?
18Fundamentals of Hypothesis Testing
- Based on what we know, we form a hypothesis to
explain something that we dont know - Generally, this hypothesis takes the form of
Yf(x1,x2...xk) - We gather data and devise a test to evaluate the
hypothesis testing the effect of the xs on Y - We assume that the null hypothesis is true
- We then look for compelling evidence to reject
this hypothesis - If we reject the null hypothesis, then we accept
the alternative hypothesis - If we fail to reject the null hypothesis, then we
have insufficient evidence to accept the
alternative hypothesis
19Hypothesis and Decision Risk
State a Null Hypothesis (Ho)
Faced with two risks of making a wrong
decision Type 1 Error Alpha Risk Type 2 Error
Beta Risk Type 1 a example Not sending a
denial balance to patient when you could Alpha
Risk Type 2 b example Sending a denial balance
to patient when you shouldnt Beta Risk
Gather evidence (a sample of reality)
DECIDEWhat does the evidence suggest? Reject
Ho? or Fail to Reject Ho?
20A Practical Hypothesis Test
S T A T E O F R E A L I T Y
No Alarm
Alarm Sounds
N O F I R E
Correct Decision Confidence 1 - alpha
probability
Type I Error alpha probability
Correct Decision Power or 1 - Beta probability
Type II Error Beta probability
F I R E
21How a Hypothesis Test Works 2 Possible States
of Reality
- Either we have No Fire, or a Fire Exists.
- Imagine that the smoke detector has a specified
set point in terms of particles/cc
Null Hypothesis True, No Fire
Area to right of trigger is probability of
committing an alpha error
Area to left of trigger is confidence or 1 -
alpha
Random distribution of particle counts in normal
air
Detector Set Point
Area to right of trigger is the power of the
test 1 - Beta
Null Hypothesis False, Fire Exists
Area to left of trigger is probability of
committing a beta error
distribution of particle counts in Smoke -
filled air
22Hypothesis Testing
- After data is collected, statistical scores can
be calculated In Microsoft Excel or
statistical software such as Minitab
A probability (P) value is one statistic
calculated to help determine if null hypothesis
is true or false
If P is low, then Ho must go!!!
- Small P-Value
- Ho is Rejected
- Large P-Value
- Ho is Not Rejected
23Hypothesis Test Statements
A) If p is low (less than or equal to alpha)
reject Ho and make the statement I am (1-alpha)
sure Ha is true B) if p is not low (greater
than alpha) fail to reject Ho and make the
statement I have insufficient evidence to
demonstrate Ha is true
24How Low Must P Be ?It Depends
- We would like there to be less than a 10 chance
that these observations could have occurred
randomly (? .10) - Five percent is much more comfortable (? .05)
- One percent feels very good (? .01)
- This alpha level is based on our assumption of
no difference and a reference distribution of
some sort - But, it depends on interests and consequences
For most cases use .05
25Proving the Null Hypothesis
- Minnesota Senate Election Results
- Ho Al Franken Norm Coleman
- Ha Al Franken ? Norm Coleman
- alpha 0.05 (5 risk Factor)
- If Vote in Minnesota allows rejection of Ho, they
Project a winner. - If Vote does not reject Ho, they say...
Too close to call !
26Hypothesis Tests - Healthcare insurance denial
type
27One Sample testAre Patient Responsibility denial
balances within 100 or less?
- Null Hypothesis (Ho) Patient Responsibility
denials are less than 100 and therefore all PR
denials received from Insurance Carriers should
be auto billed to Patient - Alternate Hypothesis (Ha) Patient Responsibility
denials are not less than 100 and therefore PR
denials received from Insurance Carriers should
not be auto billed to Patient
28Minitab - Output
One-Sample T Patient Resp Balance Test of mu
100 vs not 100 Variable N Mean StDev
SE Mean 95 CI T
P Balance 1828 277.4 509.4 11.9
(254.064, 300.803) 14.89 0.000
A P-Value !
Ho PR Denial 100 Ha PR Denial 100
Should we auto bill patient for all Patient
Responsibility Denials?
29Other Tests / Charts willConfirm the Null
Hypothesis is False
Ho PR Denial 100 Ha PR Denial 100
The 100 target to auto bill patient is not
within the confidence interval range
30Butthe data for our Denials study is non-normal
A rule of thumb with Hypothesis testing is to
understand whether the Data under study is from
a Normal or non-normal distribution. Once again
a Small P-Value (lt.05) indicates that the Null
Hypothesis In this case is false (The data a
normal distribution)
31Therefore try a 1 Sample Non-Normal Data Test
(to test
medians vs. means)
Wilcoxon Signed Rank Test PR Balance Test of
median 100 versus median not 100
N
for Wilcoxon Estimated
N Test Statistic P Median Balance
1828 1826 1243988.5 0.000 188.1
Ho PR Denial 100 Ha PR Denial 100
If P is low, reject Ho
32How do the 3 top Patient Responsibility denial
reasons compare?
Another PR denial scenario Another study ! Why
are we seeing PR type denials gt 100
- Null Hypothesis (Ho) Patient Responsibility
denial reasons (1) Insurance coverage/record
error (2) secondary claim not received by
Carrier (3) denial is patient responsibility -
have the same impact. - Alternate Hypothesis (Ha) Patient Responsibility
denial reasons have different impact
33Test for Equal Variances
- Are the variances for the 3 Patient
Responsibility denial reasons the same or are
they different? - Many statistical procedures, including analysis
of variance, assume that although different
samples may come from populations with different
means, they have the same variance - This is a (usually) buried assumption of an
Analysis of Variance. Performing this test will
prevent you from making incorrect conclusions in
certain circumstances.
34In Minitab select STATgtANOVAgtTEST FOR EQUAL
VARIANCES
Coverage Error
B for Normal L for non-normal
No Claim 2ndary claim not received by Carrier
Bill Patient
35Other Graphical Representations
- Lets also look at the Main Effects Plot and the
Interval Plot - These two plots provide different graphical
representation of the differences between the
three factors - Main Effects provides just the means
- Interval provides means and different views of
the confidence of those means - Lets take a look at each...
36Main Effects Plot
The main effects plot highlights that higher PR
denial balances result from a secondary claim not
being received by the carrier. Root cause
investigation required with primary and secondary
carriers
37Interval Plots
An interval plot highlights the mean measurement
and variability of the data Root cause
investigation required with primary and secondary
carriers
Mean
Confidence Interval 95 certainty that this
is true value of population mean
38Boxplots
- The Boxplot is another graph/method for looking
at the data that may be easier to see differences
in the distributions - Boxplots show the spread (variability) and center
of the data
39100
75
4th Quartile
3rd Quartile
50 (Median, not the Mean)
2nd Quartile
1st Quartile
25
Quartiles rank order the data from lowest to
largest value
0
Not including any Outliers
40Boxplot Outliers
Boxplot Outlier - Any data value that exceeds
either the Upper Limit or Lower Limit as
calculated below UL 3rd Quartile 1.5 x ( 3rd
Quartile - 1st Quartile ) LL 1st Quartile - 1.5
x ( 3rd Quartile - 1st Quartile )
Maximum of 257.000 is greater than UL of 170.5
which is why there is an outlier
identified at the top of the previous slide
41Back to the Top Patient Responsibility Denial
Reason
- Prior analysis revealed No Claim denial reason
was a key variability
driver - No Claim primary carrier partial payment
received but balance did not transmit to
secondary carrier - This was a surprise to the Billing Insurance
follow-up analysts leading to investigation of
secondary carriers with No Activity Since
Filing Denial Types
Investigation Action Medicare secondary
claims not being received by Medicaid. Provider
identifier and taxonomy code issues Action
involved manual rebilling of claims to Medicaid
42Can any of this type of analysis be applied in
your areas?
- Where can you use Hypothesis testing in your job
or project?
43Determine plan before Analysis and Execution
- Multi-variance pre planning provides for
- Statement of Objective
- List of Key Process Input Variables (KPIVs) and
Key Process Output Variables (KPOVs) to be
studied - Ensure Measurement Systems are capable
- Sampling plan approach
- Method of data collection
- Team member involvement
- Clear responsibilities assigned
- Outline of data analysis to be performed
44Key Multi-Vari Analysis and Execution Steps
- 1. Collect data
- 2. Analyze data
- Is the process stable, in control?
- Which are the key noise variables affecting the
output variable? - Which are the key controlled variables that
influence the output variable? - 3. Investigate root cause and develop action
plan - 4. Implement improvement actions
- 5. Measure progress
- 6. Identify prioritize key variables for
Control Plan
45Billing Charge capture case studies
- Insurance Claim Denials Reduction
- Hospice Billing Charge Capture
- Intravenous (IV) Solutions Charge Capture
46Case Study 1 Insurance Claim Denials Reduction
- Project Purpose Background (April December,
2008) - The purpose of this project is to focus on
reducing the number and amount of insurance
carrier denials for claims submitted by Gundersen
Lutheran Clinic for reimbursement. - Objective is two fold
- Reduce the incoming rate of new claim denials
- Reduce the backlog of unresolved denials
- Project Justification and Benefits
- The number and amount of Insurance claims denials
have increased by more than 70 during 2007.
Baseline dollar amount as of March, 2008 23
Million - Insurance claim denials result in bottom line
financial impact with unresolved denials
resulting into write-offs
47Team Member Involvement
and Data Gathering Approach
- Team agreement to focus on gathering data to help
- answer some key questions
- What are the sources of denials?
- Which insurance carriers?
- Which clinic departments?
- Which physicians?
- What is the total impact of denials on Accounts
Receivable? - What is the denial rate (both incoming and
backlog)? - How much AR is tied up in denied accounts?
- How much cash/margin is lost due to denial
write-offs? - What is the resolution rate on denied accounts?
- How quickly are denials resolved?
- Which denial types are easily resolved?
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50- Initial Data Challenges
- Historical data unreliable lack of tracking
- Difficult to identify denials which were
- Resolved by resolution efforts versus
- Written off
- No measurement system in place to track new
denials - Poor categorization of denial reason codes
- But practically it was clear that insurance
claim denials activity was impacting business
performance
Gundersen Lutheran Clinic Annual Gross Revenue
800 M Accounts Receivable 120 M
51Pareto Chart
Initial attempt for denials prioritization
indicated data source was adequate but needed
refining. Had to spend time mapping multiple
denial codes (remark codes) to a single denial
reason in order to properly identify 20 of the
problems causing 80 of the denial performance
American National Standards Institute
(ANSI) Claim Adjustment Reason Codes Over 250
different industry denial codes plus other types
used by Insurance Carriers
52Denials Data Source Refinements
Once properly capturing relevant data began to
Pareto top denial reasons by Insurance Carrier
Types Insurance Carriers Departments Physicians Pr
ocedure Types Billing Insurance Follow-up
Staff
53Mapping of Multiple Denial Codes
Denial Reason Coding Error
- Same Approach for
- Provider Billing missing
- Lack of Prior Authorization/Pre-certification
- Registration Errors
- Billing Errors
54Categorizing Mapping the denial code data
helped prioritize
Prioritize by Denial Dollars and...
55.and by Denial Counts
56Denials Backlog Problem
Commercial Primary
Govt Secondary
Govt Secondary
Commercial Primary
Investigation revealed high dollar balances for
primary carriers lower count volume But cant
ignore lower dollar balances Lower dollar
balances for secondary carriers significant
DAILY count volume
57Denials Backlog Study
- Denials backlog defined for Gundersen Lutheran
- Claims partially paid or fully rejected by
Insurance Carrier - Claims with No Activity Since Filing (no response
from Insurance Carrier since 45 days of claim
filing) - Denials requiring resolution by Billing
Insurance Follow-up staff - Carrier resolution (phone call, written appeal,
rebills) - Transfer to patient responsibility
- Denial is a valid write-off
- For several reasons the backlog grew to
unmanageable levels (process change did not
follow organization / system changes)
58Denials Backlog Study
An initial study looked at denials volume by
staff worklists
- Notice any differences?
- Number of denials by analyst
- Hours spent per day on worklist
- Supervisor or staff list
- Insurance Carrier Type
- Claim require coding
- Billing number needed for Provider
-
1
2
3
4
5
6
59Denials Backlog Study
Then needed to understand the incoming volume of
new denials
Coding
Provider Billing
Incoming Denial Dollars
Coding
60Denials Backlog Study
Incoming Denial Counts Investigation revealed
small dollar balances were filtered to a general
supervisor worklist quickly accumulated
secondary claims and/or small balances not
economical to pursue
61Top Actions from Initial Study
- Identified additional Lean project involving
Provider billing numbers Credentialing to
Billing sub-processes - Transitioned responsibility from Credentialing to
Billing group - Streamlined front end requirements to gather
necessary provider billing documentation from
Human Resources Clinic Departments - Realigned Coding staff responsibility for denials
resolution - Action plans developed with top Commercial and
Government carriers - Significant gap identified with cross over claims
from Primary to Secondary carrier (Medicare to
Medicaid system edit failure) - Top Commercial carrier transmitting high volume
of general denial codes (Claim lacks information)
- Implemented new measurement system for Denials
activity tracking
62Denials Management Tracking Model
There was no baseline or tracking of incoming
denials activity
63Denial Reason No Provider Billing
NumberPrioritization Step 1
64Denial Reason No Provider Billing
NumberPrioritization Step 2
65Provider Billing Number Issue
To implement process improvements for obtaining
provider billing s had to understand the
various reasons Which reason is the primary
cause for this type of Denial ?
Billing not obtained when hiring new provider
Billing expired and needs renewal
Additional billing not obtained when provider
goes to new location
66Provider Billing Number
Can root cause of not having provider billing
in place be due to Different Insurance
Carriers? Different Physicians?
67Provider Billing Number Learnings
- Emphasized need for improving front end processes
versus all work on back-end resolution - Focusing on other upstream processes which link
to a denial - Registration, insurance set-up errors
- Prior Authorization / Pre-certification
- Physician referrals
- Physician dictation and billing packet
documentation - Coding of claims
68Project start at April, 2008
Progress in 2008 Continue Control Plan
monitoring in 2009 and Phase 2 actions
69Case Study 2Hospice Billing Charge Capture
- Project Purpose Background (May October,
2008) - The purpose of this project is to improve the
process of billing for services rendered and
properly capturing charges for nursing home type
visits reimbursable by Medicare
- Project Justification and Benefits
- The amount of unbilled services has grown to over
1 Million - An undetermined amount of charges for nursing
home visits have not been entered into the
clinical/financial system
70Initial process review indicated gaps
between clinical teams and the Billing group
- New system
- Roles responsibility changes
71Investigation Approach
- Limited baseline history of unbilled amounts but
Clinical Director raised initial concern based on
department financial reviews - Even with limited history for unbilled amounts
data confirmed enough of a trend to signal an
issue
72Investigation Approach
- Initial team meetings between clinical and
billing teams quickly identified gaps with some
simple Six Sigma Lean tools - Process Mapping
- Responsibility Matrix
- Cause Effect matrix prioritization, FMEA
- Practical discussion revealed inputs into the
system by clinical teams were being hung up in
the system and not passed or visible to billing - Incorrect service types being selected by
clinicians for nursing home visits - Lack of connectivity between Clinical and Billing
teams
73What is the primary source of unbilled charges?
It was quickly determined what department to
focus on for unbilled charges
74Process error Incorrect service codes selected
for nursing home visits
75Progress Report
Oh, oh ?
Actually result of process cleanup. Along with
unbilled amounts discovered charges not yet
posted (incremental revenue for charges booked at
month end) Increase in unbilled amounts caused
delay in charge entry
76Hospice Billing Charge Capture Key Learnings
- Co-location of charge entry/billing analyst with
Clinical team - Proper system security access for clinical and
financial teams - Education to clinicians on service code entry and
mistake proof of system to flag for incorrect
codes
77Case Study 3IV Solutions Charge Capture
- Project Purpose Background (June October,
2008) - The purpose of this project is to implement a new
process to properly support the charging of
Intravenous (IV) Solutions as dispensed from
Pyxis med stations
- Project Justification and Benefits
- Hospital operations are transitioning to the EPIC
platform for the inpatient record and inpatient
order entry portion of Gundersen Lutherans
overall electronic health record in November,
2008 - A process for charging IV Solutions needs to be
implemented in advance as part of EPIC readiness
deployment and to ensure revenues are captured
during this interim period
78Primary Process Change
Nurses administering IV solutions must
capture the record in the Pyxis med station for
charging
Inputs
Outputs
IV Charging Process
Charge capture IV billing Compliance rate of
usage vs. billing
IV inventory usage Remote stock of
IVs Nurse Pyxis Med station Pink Sheets
79Data Challenges
- Creation of reports from different source systems
to implement a measurement system
for tracking IV charge compliance - Inventory usage report
- Pyxis med station billing report
- Invision billing report (for operating units not
utilizing Pyxis) - Manual tracking of Pink Sheets for operating
units without Pyxis or Invision
80Compliance Minimum Target Rate 50
Monitored initial weeks of implementation and
targeted additional education and support needed
for operating units / departments Any
differences by Department?
81Targeting some Key Input Variables
- Compliance Ratios
- Could be improved
- With some effort
- For departments without Pyxis med stations
improve manual method of capturing charges on
pink sheets - Use Nurse Education to assist specific
departments - Some departments used a stamp method as reminder
-
82Progress Report
Objective Increase compliance rate prior to
EPIC deployment
83Week 1 compliance rates by Department
Final Week compliance rates by Department
84Mike ONeill Efficiency Improvement
Leader Gundersen Lutheran Health System Mike
ONeill is a Master Black Belt, Efficiency
Improvement Leader for the Gundersen Lutheran
Health System in La Crosse, Wisconsin. Mike
joined Gundersen in March, 2008 after spending 23
years in industrial manufacturing with Trane, an
Ingersoll-Rand Company. Mike became a certified
Black Belt and Master Black Belt during his
tenure with Trane. He was the Six Sigma Leader
for the commercial global finance team and led
multiple transactional projects involving the
order to cash cycle. His last assignment at
Trane was Global Customer Quality Leader having
responsibility for all warranty processes and
policies, collecting customer quality
information, establishing customer focused
metrics, and timely claim resolution. Since
joining the Healthcare industry Mike has been
leading projects and mentoring project leaders in
the application of Six Sigma in areas of revenue
charge capture and billing process improvement.
Mike has a bachelors degree in business
administration and economics from the University
of Wisconsin-Stevens Point and a masters degree
in business administration from University of
Wisconsin-La Crosse.