Dr. Dalia El-Shafei

Assist.Prof. of Occupational Medicine

http://www.slideshare.net/daliaelshafei

Ongoing, systematic collection, analysis, andinterpretation of health data essential to theplanning, implementation, and evaluation ofpublic health practice, which is closely integratedwith the timely dissemination of these data tothose who need to know.

Surveillance programs (i.e., 2ry prevention)should be designed to support programs intendedto control workplace hazards (i.e., 1ryprevention).

Su

rvei

lla

nce

pro

gra

ms

Identifying cases

Medical screening;

Health care provider reporting

Employer case reporting

Mo

nit

ori

ng

tre

nd

s

Health effects surveillance

"Occupational illness"

Occupational diseases "OD"

Work-related diseases "WRD"

Hazard surveillance

Assessment of workplace

hazards

Identification of target organ

toxicities for each hazard

Selection of a test for each screenable

health effect

Development of action criteria

Standardization of the testing

process

Performance of testing

Interpretation of test results

Test confirmation

Determination of work status

NotificationDiagnostic evaluation

Evaluation and control of exposure

Record keeping

•Exposure assessments & risk assessments for target organ damage.

Steps 1, 2, 3

•Development of action criteria in response to medical test results. Guidelines by consensus groups, such as the Biological Exposure Index (BEI) of the ACGIH, and OSHA standards are available for selected indicators.

Step 4

•Standardization of test procedures & quality control,

•Provision of information to employees about the tests & written evidence of informed consent.

•Confidentiality of results “Record access control system”.

Step 5&6

•Interpretation of the test results should be based on several factors, including the predetermined action level criteria, and exposure data for the individual.

•Abnormal results should be reconfirmed.

Step 7&8

•Removal of the employee from further exposure

•Legal provisions to safeguard wages and benefits in the event of job transfer due to such a reason.

•Employees themselves should be notified of the results, in addition to statutory notifications.

•Further medical evaluations may be indicated, including referral to the appropriate specialist.

Step 9,10&11

•The work environment of the employee with an abnormal screening result has to be re-evaluated.

•Measures should be implemented to reduce the exposure to safe levels.

•Record keeping: Medical records, records of notifications, exposure evaluations and resulting environmental modifications.

Step 12&13

Physician

• Design and administration of screening programs.

• Provide all medical test results to the employee, along with an interpretation of the abnormal tests.

• Ensure that appropriate medical follow-up of abnormal test results.

• Ensure that if worksite exposures were responsible for abnormal test findings, these exposures are controlled to an acceptable level before the employee returns to work

• Ascertain whether or not the employee’s coworkers with similar exposures are at risk, and if so, the appropriate action that should be taken (e.g., screening).

• Medical results should be released by management if such knowledge would prompt action to protect the health of employees.

Employer

• Providing unrestricted access to medical screening for employees at risk

• Providing exposure information (e.g., job history and results of environmental sampling)

• Maintaining a safe and healthful workplace

Employee

• Providing accurate information (e.g., medical history)

• Cooperating with medical testing procedures

• Assume personal responsibility for changing the behavior to reduce the risk

Employers are required to provide employees with access to

medical screening examination when the employees are

exposed to certain hazards.

In a few instances, decision models are provided (e.g., Lead and

Cotton Dust Standards) that guide physicians in their evaluation

of results and in their recommendations for action.

In most instances, little or no guidance is provided in the

interpretation of results.

OSHA requires that records be maintained for the duration of

employment plus 30 years, and that access of the employee to

his or her personal records be provided on request.

A

• 2-Acetylaminofluorene

• Acrylonitrile

• 4-Aminodiphenyl

• Inorganic arsenic

• Asbestos

B

• Benzene

• Benzidine

• Bischloromethyl ether

C

• Cadmium

• Coal tar pitch volatiles

• Coke oven emissions

• Cotton dust

D

• Dibromochloropropane

• 3,3′-Dichlorobenzidine

• 4-Dimethylaminoazobenzene

E

• Ethylene oxide

• Ethylenimine

F

• Formaldehyde

H

• Hazardous waste

L

• Lead

M

• Methylchloromethyl ether

N

• Alpha-naphthylamine

• Beta-naphthylamine

• 4-Nitrobiphenyl

• Nitrosodimethylamine

• Noise

P

• Beta-propiolactone

Regulations have been developed in many cities, states, and

countries that instruct healthcare providers to report suspected

cases of occupational illness or injury to an office of government.

To develop a systematic approach to the use of reports

received from healthcare providers in the US, NIOSH developed

the Sentinel Event Notification System for Occupational Risks

(SENSOR).

Once reports are received and confirmed by the health

department’s surveillance centers, an active response occurs.

Three possible actions may take place:

• Management of the individual case;

• Screening of coworkers with similar job exposures; and

• Investigation of the worksite.

Surveillance systems designed to monitor trends for

occupational disorders or exposure usually rely on existing

records collected for purposes other than surveillance.

These records are coded or modified in some way to

make them suitable for analysis.

Each data source has certain limitations and advantages

that must be considered in assessing the usefulness of the

data for surveillance purposes.

Pre-existing healthcare & vital records

Employer case reporting

Workers’ compensation

data

Biologic monitoring

data

National health surveys

Exposure surveillance

systems

Death certificates (including those of fetal deaths), birth certificates, hospital

discharge records, office records of healthcare providers, and insurance claim files.

Limitations:

• Information on the occupation of the patient is often not in the record;

• Physicians often fail to recognize disorders caused by occupational hazards;

• Misclassification or omission of conditions and occupations of interest.

Advantages:

• Records are available at modest cost;

• Records are coded using generally accepted code schemes (e.g., ICD).

Improve awareness among healthcare providers of the impact of work on health.

In the US, employers are required by OSHA to record

occurrences of occupational illness and injury on a form maintained

at the worksite (called the OSHA log).

The responsibility for completing this record often falls to an

individual who has had no medical training and guidance in

determining what should be recorded. Studies have shown that many

disorders, particularly occupational illness, are not reported in the

OSHA log.

Each year, the Bureau of Labor Statistics of the US Department of

Labor collects a sample of these records from a portion of employers;

certain categories of the workforce are not included in the survey.

This sample is used to generate national estimates for selected

conditions.

Limitations of workers’ compensation data for surveillance:

• In view of reporting disincentives and inherent difficulties in

recognizing occupational disorders, workers’ compensation data

consistently underestimate the true rate of occurrence of occupational

disorders. Furthermore, the rate of underestimation varies among

conditions, with greater under-reporting of diseases than for

occupational injuries.

• Workers’ compensation laws vary from state to state. Many workers’

compensation systems have requirements that claims be filed within a

brief time period (e.g., within 1 year) following the suspected exposure;

this requirement may present substantial barriers to filing claims for

occupational diseases of long latency (e.g., cancer).

Advantages to the use of workers’ compensation data includethe following:

• All records in the data set relate to conditions of suspectedoccupational etiology.

• Information on the job and the industry for each claimant iscontained in the record.

• The circumstances of the illness or injury are frequently describedin a way that provides understanding of the cause of the condition.

• If case identification leads to improvement of workplaceconditions, prevention of further claims should occur, thusbenefiting both the employee and the employer.

• If these data are used for surveillance purposes, technicalimprovements in the data management system (e.g., better codingprocedures or computer systems) could occur that would benefit themanagement of the workers’ compensation insurance system itself.

In summary, workers’ compensation data represent an

important source of surveillance data that can be used to

monitor trends in the occurrence of selected occupational

disorders and to identify cases for follow-up action.

Limitations:

• Biologic assays exist for only a few substances.

• Quality control programs for these analyses may be limited.

• Participation in biologic monitoring programs is often limited

to larger workplaces in which hazards are well controlled.

• Within workplaces that participate in a biologic monitoring

program, individual workers may choose not to be tested.

Advantages:

• Each test (e.g., BLL) is a specific index of exposure to the

toxic substance.

• In states where commercial laboratories are required to report

results to the state agency, data can be obtained widely and at

low additional cost.

Different countries maintain different health survey

systems.

Each year in the US, the National Center for Health

Statistics (NCHS) performs surveys of statistical samples of

the population. Within each sample, a subset of employed

persons can be identified. In each survey, health status data

and occupational listing information are collected.

The US Health Interview Survey (HIS) is a questionnaire

survey.

The National Health and Nutrition Examination Survey

(NHANES) uses both a questionnaire and detailed medical

tests to obtain health status information.

Exposure surveillance can be performed using existing

data or through the performance of worksite surveys.

Existing environmental data are most commonly

developed as part of compliance inspections performed by

the US Department of Labor (either OSHA or the Mine

Safety and Health Administration, MSHA).

Direct surveys have been performed by NIOSH: the

National Occupational Hazard Survey, the National

Occupational Exposure Survey, and the National Mining

Survey.