introduction to and overview of case based surveillance nastad global program

Introduction To and Overview Of Introduction To and Overview Of Case Based SurveillanceCase Based SurveillanceNASTAD Global Program

Overview

Discussion About:

– Epidemiological Surveillance

– Case-based Surveillance Reasoning, benefit and added value Requirements for system implementation

– How Implementation Might Look Case-based surveillance Biological and behavioural surveillance

Epidemiological Surveillance

Surveillance

What is Surveillance?– Keeping a close watch over something

What is Epidemiological Surveillance?– The ongoing, systematic collection, analysis, and

interpretation of health data essential to planning, implementing, and evaluating public health practice, closely integrated with the timely dissemination of these data to those who need to know

Why Do Epidemiological Surveillance?

To understand the disease in order to:– To prevent the disease – To protect the public’s health and wellness

To promote public health and a public health response by identifying:– Public health problems– Populations who are affected– Risk factors

Surveillance is essential for planning, implementation, and evaluation of public health practice

Methods Used for Epidemiological Surveillance

Population-based Surveys– A sample of a population is defined, sampled, and

surveyed– With modeling, findings may be generalizable

Sentinel Site Surveillance– As above, but sampling occurs only at a set number of

locations – Finding may be generalizable to some part of the

population

Case-based Surveillance– A ‘census’ of all known/diagnosed cases of a disease

Methods of Surveillance: Population-based

Demographic and Health Survey National representative household survey

– Population, Health, Nutrition Sample size:

– 5,000 to 30,000 households Regular frequency:

– +/- 5 years, to allow comparisons over time Random and representative sample of households selected

– Household: All who normally sleep there (including staff), and guests who spent the previous night

60 minutes survey with all eligible:– Men age 15-59; Women age 15-49 ; Info about children ages 0-5

Data available via www.DHS.org

http://www.dhs.org/

Types of Surveillance: Sentinel Surveillance

Sentinel (and Behavioral) Surveillance– Specific sites and population groups– Predetermined number of persons – Testing done in regular and consistent way (WHO)

Communicable diseases Antenatal Men who have sex with men Injection drug users Commercial sex workers Truck drivers

Data available via MoH’s, www.FHI.org, www.DHS.org, or other

http://www.fhi.org/

http://www.dhs.org/

Types of Surveillance: Case-based

Case-based Surveillance– Regular and systematic reporting of all cases – Stronger system if data come from many sources– A living system that is updated as cases are reported– Sensitive to outbreaks, changes in trends

Discussion

What methods of surveillance are in use in your country?

What are some pros and cons of each method of surveillance?

Do you see the data being used to guide:– Planning, implementation, evaluation?– Are data disseminated in a timely and routine

fashion?

Why Case-Based Surveillance?

Evolution of Data Needs

Need or desire for—or possible access to—epidemiologic data in countries has evolved over the past 10 years

PEPFAR I (2004): Few national level HIV care and treatment programs– Surveillance need at that time was to monitor HIV (or AIDS) in

general population to understand what was happening.

PEPFAR II (2009): Many national large scale prevention, care and treatment programs– People are living with HIV for many years; planners need

epidemiologic information about people who are diagnosed with HIV to know how to best treat and best prevent HIV.

Today: There are usable data are everywhere– Program-driven M&E and patient tracking required this.

Benefits of HIV/AIDS Case Surveillance

Provides an ongoing and comprehensive understanding of a country’s epidemic– Who– Where– When– How

Allows for better allocation of resources– Prevention– Care and Treatment

Provides context for M&E information

Leverages existing information; ‘low’ resource needs

Why Case-Based Surveillance

Basic Elements of Case-Based Surveillance

As Easy As…

HIV/AIDS Case Surveillance System: Basic Elements

A.Define what you want to know

– What do you want to be able to describe about HIV/AIDS?

– What do you want to be able to describe about trends over time?

– What do you want to be able to describe about the population?


B.Define what needs to be reported to answer your questions

– HIV infection (all stages)or

– Advanced stage HIV disease (stages 3, 4)or

– AIDS (stage 4)

Monitor HIV Disease

HIV disease sentinel events

HIV exposure(exposed infants or

sexual transmission)

HIV infection 1st positive

HIV test1st CD4 count 1st CD4

count <350

1st viral load 1st CD4

<200AIDS-related Opportunistic

Infection Death

Monitor HIV Disease






count <350



Infection Death

AIDS Case Reporting

Monitor HIV Disease






count <350



Infection Death

HIV Case Reporting


C. Define which other events should be reported to help you answer what you want to know– 1st positive test

First event for a person… sets the clock

– 1st CD4+ test How long post diagnosis are CD4 tests done? Do counts seem to be high or low?

– 1st CD4+ < 200 What is the average time from HIV diagnosis to AIDS diagnosis? How many people who are eligible for ART are on ART?

– HIV exposure (children) What happens to the babies exposed to HIV?

– Death What is the average time from HIV diagnosis to death?


D. Define who must report– Public health facilities– Laboratories– Private health facilities– Other


E. Define how cases will be linked and cleaned

– Name-based John Adams Jane Allen

– Code-based JA1268F JA1268F

F. Define how cases will be reported– Paper– Electronic– Where will cases be cleaned and de-duplicated– Where will cases be stored

Discussion

In your country:

A.Is there a need for this?

B.Do you think there is/could be interest in this?

Discussion

C. In your country, are there:

– Local data collection systems?

– Larger tracking or M&E systems?

Patient Registers

Patient Care Record

Discussion

D. Are there any existing data pathways that could be used?

Discussion

What are some questions that can be answered via case-based surveillance? And the Public Health benefit

– Do people test for HIV early or late in their infection? Implications for increased HIV transmission and years lost of life; would look to have more

‘early testers’.

– What is the average time between HIV diagnosis and AIDS diagnosis and/or death? As above. Would look to increase the time between events.

– What proportion of people who test positive for HIV enter into the treatment and care system? How can the referral system be improved to capture all?

– What proportion of people in the treatment and care system access regular and routine care? Are national standards adhered to? Are other resources needed to support routine care?

– What proportion of those eligible for ART have access? Are the national standards adhered to? What can improve access?

Some Important Considerations

The Need for a Unique Case Identifier

Patient Identification

– What it is A unique way to identify each case (person)

– Why it is important Patient identification is important if we want to have a unique

count of persons infected with HIV Patient identification allows patient tracking over time Each event is entered into the system to determine if it is a

unique (new) record. Some will be new cases; some will be an update to an existing patient in the system. Updates include:– Transition from HIV to AIDS– A pregnancy– A visit to a different clinic system– A death

Selecting a Unique Case Identifier

The case identifier must:– Be unique to the individual – Not change over time or allow time of change to be known – Be easy to identify from a clinical record– Be something that is or is derived from routinely collected data

The case identifier must be able to:– Distinguish duplicate reports for the same person– Distinguish cases with the identifier who are different persons– Allow follow-up information from the surveillance program and

healthcare provider to be easily connected with existing information

Discussion

In your country, is there something like a unique ID code in use?

Data Management and Cleaning

Data Deduplication– What it is

An evaluation and assessment of each case entered into the system to determine if it is a unique (new) case, or if it is an update on an existing patient in the system

– Why it is important Deduplication is important if we want to have a unique

count of persons infected with HIV Deduplication, and matching records to the source file,

allows patient tracking over time


Data Deduplication– How it can be done

Manually or automatically Cases are matched by certain selected criteria:

– Unique ID Code - Each record needs one for each patient Ideally, people have national identifiers (and they are

used!) before a record is entered More often a unique identifier must be established from

some combination of common demographic information The more unique, the more certainty that records are for

the same person– Combination of other variables that are somewhat unique:

Name Parents Names Date of Birth Location of Birth Location of Residence

Records that match are appended to each other to track over time


Data Validation– What it is

A review of data to see that what is submitted is accurate Examples:

– Are the report dates more recent than the last data transfer?

– Does everyone have a birthdate?– How many fields are completely empty?

– Why it is important Speaks to the quality of the data People make mistakes. The wrong file can be uploaded, data

can be deleted, or records can be shifted.– How it can be done

Chart review (sub-set) vs. submitted data Record review (sub-set) vs. submitted data

A Central Management System

Why? De-duplication of cases between and among systems to provide a unique count of cases

– Patient tracking within and between networks– Better trend monitoring– Additional data source to triangulate with existing

prevalence estimates and/or program outputs

Greater controls for patient privacy and data confidentiality

Ownership of surveillance data buy government to enable leadership in public health functions

Discussion

In your country, is data management and data validation visible or available?

Putting the Pieces Together

~ an example from Haiti

Strategic Planning

1. What is the goal?– Stop mother to child transmission

2. What is needed to reach the goal?– Test all pregnant women– Provide treatment, care, outreach, support– Provide follow-up after birth for exposed children

3. What resources and systems exist?– Patient registers– Some reporting pathways– Case managers

Sample:Reporting the Spectrum of HIV/AIDS

Morbidity and Mortality

Pregnancy+HIV+ Test

Pre-NatalPre-Natal and and PediatricPediatric Surveillance Surveillance

Prophylaxis at Delivery

1st ART (PMTCT Prophylaxis)

Entry to PMTCT

Prophylaxis Post-Delivery

+ while Nursing

Infant Visit within 72 Hours

Infant PCR

Infant HIV Screen (6 months)

Infant HIV Screen (18 months)Entry to ART/Care

Entry to Care (if HIV+)

Infant Prophylaxis after birth

(AZT, NVP)

MESIMonitoring, Evaluation,

and Surveillance Interface

NationalEMR

(I-TECH)

Local EMRs

VCTPMTCT

PEPFARTreatment and

Care

GHESKIO/PIHTreatment and Care

HIV/AIDS Case Surveillance

Centralized Database

Epidemiologic Analyses

Periodic Reports

Quality Assurance

Laboratory-Based

Reporting

(MESI, Haiti, Daily/Weekly)-“Surveillance”-Online

(MESI, Haiti, Daily/Weekly)-“Surveillance”-Offline

(I-TECH, WA, Biweekly/Monthly)-EMR

(GHESKIO, Haiti, Biweekly/Monthly)-EMR

(PIH, MA, Biweekly/Monthly)-EMR

HAITIHIV SURV

MOH

MESI

ITECHMESI 1

De-duplication

Surveillance Loop

Sample Roles and Responsibilities

Sample Data Collection Tool

Proposed:PMTCT Case ‘Flagged’ by case surveillance systemSite level staff contacted to arrange for follow-up Sentinel event tool used to track woman pre- and post-natallyCues for staff follow-up:

– Tool

– User interface

– National data system

Summary

Case Based Surveillance

When devising or expanding a case-based surveillance system, priorities include:– Knowing what you want to know

and– Tracking what you want to track

However, you might also consider:– Best use of existing resources

where resources include:– Data systems, data variables, data flow, and data-

personnel

introduction to and overview of case based surveillance nastad global program

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