1. The Summary Quality Index (SQUID): A summary measure for multiple quality indicators in primary care
Paul J. Nietert, PhD
Ruth G. Jenkins, MS
Andrea M. Wessell, PharmD
Sarah T. Corley, MD
Steven M. Ornstein, MD
The Medical University of South Carolina
AcademyHealth, Boston MA June 2005

2. Accelerating Translation of Research Into Practice (A-TRIP)
AHRQ-funded demonstration project to improve preventive services
92 ambulatory care practices around the U.S.
All practices use an electronic medical record.
All are part of Practice Partner Research Network (PPRNet).
Quarterly data extracts from each practice

3. PPRNet Sites

4. Background
Quality indicators are helpful tools for translating research into clinical practice.
Providing feedback to clinicians on these indicators and assisting them with process change through on-site visits by our research staff have been shown to help them make system changes that improve the quality of the care they provide.

5. A-TRIP Methods
We provide practice reports, showing practice’s performance on 78 unique quality indicators from 8 clinical domains:
Hypertension
CHD and Stroke
Cancer
Immunizations
Inappropriate Rx in Elderly
MH/SA
Respiratory/Infectious Disease
Nutrition and Obesity

6. Example: DM pts with HgbA1C in past 6 months

7. The Challenge
Analyzing improvements in 78 quality indicators presents challenges:
Many measures are correlated with each other
LDL < 100 (CHD pts)
LDL < 100 (DM pts)
Some lab measures have different targets based upon morbidity
BP < 130/80 (DM pts)
BP < 140/90 (HTN pts)
Some pts not eligible for some measures

8. Methods
Goal: Design a method for summarizing the 78 quality measures that:
Is clinically relevant and interpretable
Is statistically sound
Allows for the evaluation of QI efforts over time

9. Possible Solutions
For each pt, add all 78 indicator variables together
Bad idea! (Many pts not eligible for certain measures)
Use principal component analysis techniques for analysis
Bad idea! (Too complicated to explain)
Use the Summary Quality Index
Good idea!

10. The SQUID: Algorithm
Define processes and outcomes of interest, regardless of target
BP Monitoring
LDL Monitoring
HgbA1C Monitoring
BP Control
LDL Control
HgbA1C Control
78 indicators reduced to 32 processes & 5 outcomes

11. The SQUID: Algorithm
Create indicator variables (ei) that reflect whether pt is eligible for each process and outcome measure
PAP Test (Women > 18 yrs old)
FOBT (Men & Women > 50 yrs old)
Create indicator variables (mi) that reflect whether pt has met the target for a process or outcome, given his/her demographics and/or morbidity
If pt has DM, then BP must be < 130/80
If pt has HTN, BP must be < 140/90

12. The SQUID: Algorithm
E = The number of measures for which the pt is eligible (denominator) = Σ ei
M = The number of eligible measures for which the pt has met his/her morbidity-specific target (numerator) = Σ mi
Create a pt-level SQUID =
Create a practice-level SQUID = average of all pt-level SQUIDs M E

13. The SQUID: Interpretation
A patient’s SQUID reflects the percentage of targets met out of the total number of targets for which he/she is eligible.
A practice’s SQUID reflects the average percentage of targets achieved by their patients.

14. Results: SQUIDs as of 4/1/05
Across the 92 physician practices, adult pts were eligible, on average, for 9.7 out of a total of 37 processes and outcomes.
On average, pts met 3.7 of their eligible targets.
Across all pts, the average SQUID was 31.5%.

15. Mean Practice-Level SQUID

16. Results: SQUID Over Time

17. Notes SQUIDs can be used in patient-level or practice-level analyses.
Because it is a continuous measure, and because of its relative normality, certain linear models may be appropriate.
Examples:
Mixed effects regression models
Generalized estimating equations models

18. Conclusions
The SQUID is an effective tool to aid in the evaluation of multiple quality indicators.
Nice statistical properties
Clinically meaningful
In future research studies and quality improvement efforts that include multiple quality indicators, the SQUID should be considered as a measure of overall quality.

19. Thank you!