POSTGRADUATE DIPLOMA IN OCCUPATIONAL HEALTH

FINAL EXAMINATION

PAPER I:  EPIDEMIOLOGY AND BIOSTATISTICS
(TOTAL CREDIT IS 17% OUT OF 100%. ALL PARTS ARE WEIGHTED EQUALLY)

DATE   MONDAY 31 AUGUST 1992

TIME   9.30 - 12.30

VENUE  SEMINAR ROOM 1, DEPARTMENT OF COMMUNITY HEALTH

PART I: 

1.	Height and weight are often used in epidemiological studies as possible predictors of disease outcomes.  
	In a study to compare self-reported weight and measured weight on 10 people, the following data was recorded.

Person	Self-reported		Measured		Difference
		weight (kg)         weight (kg)
1			55				60		-5
2			56				54		+2
3			60				64		-4
4			53				55		-2
5			55				60		-5
6			79				87		-8
7			56				60		-4
8			80				81		-1
9			60				58		+2
10			56				56		 0

Test the hypothesis or compute a 95 per cent confidence interval for the difference between self-reported and measured weights.

2.	Outline the general procedure of hypothesis testing between two sample proportions.

3.	Discuss the properties of the normal (Gaussian) distribution.

PART II:  Epidemiology short questions

1.	You are an occupational medical practitioner working in an  asbestos-cement factory that has been operating since the mid- 1950's and has roughly 1 500 employees. You have noticed that  there are a number of cases of lung cancer in the factory  population.  Some of these are among smokers, others among non- smokers. You become interested in studying the occurrence of lung  cancer.  Explain the survey/s that could be designed and the  occurrence measure/s that could be used to pursue your interest  and investigate the occupational aetiology of lung cancer in this  population.  List the advantages and disadvantages of each design  that is feasible.

2.	During a 4-year period there were 532 Sharps injuries due to accidents among the personnel at certain medical laboratories.  The number of employees at these laboratories was 520 at the beginning of the period and 680 at the end.  Which measure of occurrence can be calculated?  Calculate this.

3.	What do you understand by Sensitivity
                               Specificity
                               Positive predictive value
                               Negative predictive value

	of a screening test. Use a fourfold table to illustrate your  answer.  Give one line definitions only.

4.	In a mass screening aimed at early diagnosis of HIV infection, an ELISA test is used where both the sensitivity and specificity are 99%.  Of those attending the screening, one per thousand have the disease.  What proportion of those who screen positive have the disease?.  How would you proceed with these results in hand?

5.	Of 725 female industrial workers exposed to radium in their work between 1915-29 in the U.S., 22 died of malignant bone tumours.  The expected number was 0.27.  Calculate the SMR.

6.	In a study, male vulcanization workers were compared with all working men with regard to the cumulative incidence of esophageal cancer during a 13-year period.  The results are shown in the table below.  Perform an "indirect" age standardization, i.e., calculate the SMR.

			Vulcanization Workers	Comparison Group
											No.of
			No.With		No.Of	No.With		Men
Age			Disease		Men		Disease	  (thousands)

15-24		?			651		   0			337
25-34		?			518		   6			431
35-44		?			500		  90			522
45-54		?			465		 381			507
55-64		?			211		 626			367

Total		8		   2,345	    1,103		   2,164

List some common validity problems in occupation epidemiology studies.

List some common validity problems in occupation epdemiology studies.

7.	The alcohol consumption of individuals in a random sample from a population was established.  The individuals were divided into those who did and those who did not consume alcohol.  A follow-up showed an excessive incidence of lung cancer among the consumers of alcohol.  Discuss its validity.

PART III:

Criticise the article provided by using a structured approach listing the  sort of validity problems that may be expected to be encountered  in the research process.  Cover Purpose, aim, objectives,  methods, results, discussion and recommendations.

PAPER II: OCCUPATIONAL MEDICINE AND TOXICOLOGY
(TOTAL CREDIT IS 17% OUT OF 100%. ALL QUESTIONS ARE WEIGHTED  EQUALLY)

DATE    TUESDAY 1 SEPTEMBER

TIME    9.30 - 12.30

VENUE   SEMINAR ROOM 1, DEPARTMENT OF COMMUNITY HEALTH

1.	You are asked to draw up guidelines, directed at occupational health doctors, for lung function testing in South African manufacturing industry.  Prepare a draft.

2.	Prepare the outline of a lecture, to be given to an audience consisting of health and safety officers from union and industry and health inspectors, on the health hazards and safe use of solvents.  Concentrate on general principles, using examples of the more hazardous solvents.

3.	You are the occupational health practitioner for a large clothing factory.  There have been a number of musculoskeletal complaints from workers involving the back, neck and upper limb.  Write down a strategy for helping the company and its occupational health service to solve the problem.  Include epidemiological, ergonomic and medical aspects.

PAPER III: OCCUPATIONAL HEALTH SERVICES MANAGMENT & ORGANISATION  INCLUDING SAFETY, LEGISLATION AND INDUSTRIAL RELATIONS
(TOTAL CREDIT IS 17% OUT OF 100%.  ALL QUESTIONS ARE WEIGHTED  EQUALLY.)

DATE    TUESDAY 1 SEPTEMBER

TIME    14.00 - 17.00 

VENUE   SEMINAR ROOM 1, DEPARTMENT OF COMMUNITY HEALTH

1.	You are called in to consult for a large financial institution  which owns several high-rise office blocks in Central Business  Districts across the country.  There are disturbing reports of  health-related complaints and a suspicion that productivity may  be being affected in several of these work environments.  

	Write a concise plan of action for management to follow in  investigating the problem bearing in mind all people working in,  and all processes being conducted in, a large office block.  This  should include recommendations for regular surveillance.

	Bear in mind also industrial relations aspects of introducing any  new policies which may affect work or the work environment in  such a situation.

2.	The Department of Manpower is contemplating a new system for  setting occupational exposure limits in South Africa.  You are  approached for your advice as to whether the current legislative  provision is adequate or not.  If not, you are asked to consider  a system for limit setting for South Africa.  Should South Africa  be setting its own limits?  If so, through what mechanisms?  If  not, what system should be adopted?  Should the new system take  into account the different views of interested parties?  How  might this best be achieved? Discuss the ethical issues along  with issues that are uppermost in the minds of ordinary workers,  worker organisations, management and employer organisations and  those responsible for occupational health and safety in the state  departments of manpower and health. 

3.	A local agribusiness employing around 5000 workers (includes  their dependents) producing fruit approach you with a view to  setting up an occupational health service.  The nearest town is  20 kilometers away and has only a few private GPs with a private  hospital.  The only public health service is provided parttime by  one of the GPs acting as District Surgeon.  Produce a memorandum  outlining the sort of service you think should be set up  including structural aspects such as staffing, salaries, budget  for capital and running expenses, and functional aspects in terms  of the type of services to be rendered.  Consider possibilities  of linking up with and liaising with the regional health  authorities.