Transcript Data & Research: Making Use of What We Find from STD

Los Angeles County
STD Surveillance
Data Surveillance, Sources,
Methods and Issues
Lisa V. Smith, MS, DrPH
Director, Epidemiology Unit
Los Angeles County
Sexually Transmitted Disease Program
Overview
 What are active and passive surveillance?
 Which STDs are reportable?
 What is the impact of LA County morbidity
on state and national STD surveillance?
 How are cases reported to LA County
(LAC), State, and CDC?
 What are “rates” and how are they used?
 What are the limitations and benefits of
LAC STD surveillance data?
What is Surveillance?
Systematic collection and evaluation of:
 Morbidity and mortality data
 Special reports of field investigation of
epidemics and individual cases
 Data on the isolation and identification of
infectious agents by public or private
laboratories
 Information regarding immunity levels in
certain populations
What do we do with this
information?
 Estimate the magnitude of health conditions
in at-risk populations
 Detect sudden changes in occurrence and
distribution
 Detect changes in drug resistance
 Identify changes in health care practices
 Evaluate control strategies
 Allocate resources
Data Sources
 Active Surveillance
Conditions of particular importance
(outbreaks and epidemics)
 Passive Surveillance
Routine notifiable disease surveillance
reported case by case
Active Surveillance
 Casefinding:
– Prevalence Monitoring
• Sentinel Surveillance: K-11, Juvenile
Hall, Family Planning Clinics,
Bathhouses, Syphilis Elimination
Project (MSM)
• Mass Screening: Mobile testing, Adult
Movie Industry
– Epidemiologic research: Primary HIV
infection
Passive Surveillance
 Accounts for most of the reported cases
 Relatively simple compared to active
surveillance
 Limited by variability and incompleteness
 May fail to identify outbreaks
 Usually augmented by active surveillance
Which STDs are reportable?
Health Care Provider
Clinical Laboratory
 Syphilis*
 Syphilis (Treponema
pallidum)
 Gonorrhea**
 Gonorrhea (Neisseria
 Chlamydia**
gonorrhoeae)
 Chancroid**
 Chlamydia (Chlamydia
 PID**
trachomatis)
 NGU**
California Code of Regulations, Title 17, Public Health, Section 2500, 1996
*Report by FAX, telephone, or mail w/in one working day of identification
*Report by FAX, telephone, or mail w/in seven working days of identification
Reported Sexually Transmitted Diseases
United States, 2003
Congenital
Syphilis
413
(<1%)
Chlamydia
877,478
(69.0%)
P&S
Syphilis
7,177
(<1%)
Early Latent
8,361
(<1%)
AIDS
43,158
(3.6%)
Source: CDC Sexually Transmitted Disease Report, 2001
Gonorrhea
335,104
(26.4%)
Reported Sexually Transmitted Diseases
Los Angeles County, 2003
Congenital
Syphilis
28
(>1%)
P&S
Syphilis
442
(>1%)
Chlamydia
36,555
(78%)
Early Latent
365
(>1%)
AIDS
1,399*
(3%)
*Provisional data due to reporting delays
Source: LAC DHS STD/ACD Programs Provisional Data, 2003
Gonorrhea
8,008
(17%)
What is the Impact of LAC
Morbidity on STD Reporting
in CA & US*
 36,555 Chlamydia
(31% CA; 4% US)
 8,008 Gonorrhea
(31% CA; 2% US)
 442 P&S Syphilis
(34% CA; 6% US)
 365 Early Latent
(54% CA; 4% US)
 28 Congenital Syphilis
(47% CA; 7% US)
*LA, CA, CDC STD Surveillance, 2003
P&S:chancres/lesions (90 days-6 months); EL asymptomatic (w/in 12 months)
How are cases reported
to the STD Program?
 Health providers use forms to report STD
cases to the health department
 STDP uses a “dual” reporting system to
gather information on STD morbidity
– Confidential Morbidity Forms (CMRs)
• Submitted by health providers
– Laboratory Report Forms
• Submitted by laboratory facilities
Medical Provider’s STD Reporting Form
Medical Provider’s STD Reporting Form
Example of Laboratory STD Reporting Form for CT/GC
STD Surveillance Process
 Case Definition: Differential clinical
diagnosis of reportable STDs to distinguish
between cases and noncases
 Population Definition: Identify area of
interest to determine residency and
population denominators
STD Surveillance
Confidential
Morbidity
Reports (CMR)
+
Laboratory
All CA
Slips
county
reports
LAC STD Program
Data Entry/ Field Services
Data Cleaning / Transmission
California Department
Of Health Services
STD Control Branch
Centers of Control
and Prevention (CDC)
Public Health
Action
1. MMWR (Morbidity and Mortality Weekly Report)
2. Requests for Proposals
3. Healthy People 2010
85.2
LA
(2003)
73.9
CA
(2003)
116.2
US
(2003)
Why do we use rates
and not absolute numbers?
 Total number of reported cases appears to
be adequate, but are these numbers
comparable?
Absolute Numbers
(Males Only)
Black Hispanic
Reported
Chlamydia
Cases in
2001
1,965
2,720
Asian
White
181
622
STD Rates
=
multiplier
Number of new events in specific period
X 10n
Average population* during specific period
Essential for comparing dx in different populations:
Pop A: 1,000/10,000 = 100 cases per 1000 population
Pop B: 1,000/1,000,000 = 1 case per 1000 population
*Assumes average population and “population at risk” are comparable.
Population Rates
(Males Only)
Reported
Chlamydia
Cases in
2001
Black
Hispanic
Asian
White
1,965
2,720
181
622
2,297,208
593,633
1,590,586
118
30
39
*Population 396,614
Estimates
Rate per
100,000
Population
*2000 Estimates
495
How are these rates used?
Figure 1. Chlamydia Reported Rates by Year,
United States, California, and Los Angeles County (LAC), 1997-2001
350
332
1. Identify overall trends
310
294
Rates per 100,000 population
300
283
277
249
250
251
260
258
239
229
252
234
208
200
207
United States (1)
California (2)
LA County (2)
150
1997
1998
1999
2000
2001
Year
(1) CDC. Sexually Transmitted Disease Surveillance, 2000 , September 2001, p. 83.
(2) California Department of Health Services, STD Control Branch, Chlamydia, Cases and Rates by Health Jurisdiction, California, 1997-2001 Provisional Data.
Note: The 2001 US rate w as extrapolated from the 1997-2000 rates since the 2001 CDC rate w as not at available at the time of this w riting.
Population per 100,000
Chlamydia Rates by Gender
500
450
400
350
300
250
200
150
100
50
0
2. Describe disease
patterns
Male
US
CA
LA
Female
Age Group
3. Describe spatial
distributions
4. Target interventions
Additional Resources
National Center for
Health Statistics
 Nation’s principal health statistics agency
 Data are used to guide actions and policies,
as well as:
– Document health status of populations and important
subgroups
– Identify disparities in health status by race/ethnicity,
socio-economic status, region, etc.
– Monitor trends in health status and health care delivery
– Support biomedical and health research
– Evaluate the impact of health care
National Surveillance Reports
(www.cdc.gov/nchs)
 National Health and Nutrition Examination Survey
(NHANES)
– Contains important information on sexual
behaviors
 National Health Interview Survey (NHIS)
– AIDS Knowledge and Attitudes Supplement
 Young Risk Behavior Surveillance System (YRBSS)
(www.cdc.gov/yrbss)
– Survey monitors sexual behaviors that contribute to
unwanted pregnancies and STD/HIV
 UCLA ISSR website:
http://www.sscnet.ucla.edu/issr/da/catalog.htm
Data Limitations
 Incomplete case reporting
– Reporting delays
– Missing information
– Underreporting (asymptomatic cases)
 Reporting bias
– Stigmatized condition
– Public vs. Private
How Can We Improve Data
Quality?
 Improve data retrieval system
– Phone Shop
 Increase provider awareness of reporting
regulations
– In-services
– Mass Mailings
– In person visits
 Implement CDC NEDSS web-based surveillance
What are the Benefits of
STD Surveillance?
 Though flawed, STD surveillance data
provides
– the “best estimate” of magnitude of
disease in at-risk populations
• Numbers are the “tip” of the iceberg
– the basis for epidemiologic research
– a system to monitor compliance with
CDC treatment guidelines
Key Points to Ponder
 To date, six STDs are reportable in California
 Chlamydia is the most frequently reported STD
in the United States
 Los Angeles accounts for 1 of 3 STD cases in
California and 1 of 25 cases in the United States
 Most of the STD data come from passive
surveillance systems and “dual” reporting
 Data limitations include incomplete case
reporting and reporting bias
 Nevertheless, STD surveillance data provides
the “best estimate” of magnitude of disease in atrisk populations
Resources
 Los Angeles County
http://lapublichealth.org/std/
 California
http://www.dhs.ca.gov/ps/dcdc/pdf/cdtables/febcm
03.pdf
 Centers for Disease Control and Prevention
http://www.cdc.gov/
 http://www.cdc.gov/nedss/