Objective structured clinical/practical examination (OSCE/OSPE).
The conventional clinical and practical examination is beset with several problems. Although marking should depend only on student variability, patient (or in the case of practicals - experiment) variability and examiner variability significantly affect scoring. In fact, the subjectivity involved may reduce the correlation coefficient between marks awarded by different examiners for the same candidates performance to as low as 0.25. The marks awarded also reflect only the global performance of the candidate and are not based on demonstration of individual competencies. Problems in communication significantly affect the outcome. Attitudes are usually not tested at all by the conventional examination. Even in clinical skills, often the student is questioned only regarding his final conclusion. The ability to examine a patient and arriving at that conclusion is not observed by the examiners. The final score indicating his overall performance gives no significant feedback to the candidate.
These defects of clinical and practical examinations have been realised for long and have given rise to attempts at improving the current scenario,,. All these attempts are relatively new and are still in the process of being tried out.
An earlier innovation in this regard is the objective structured clinical examination (OSCE) later extended to the practical examination (OSPE) described in 1975 and in greater detail in 1979 by Harden and his group from Dundee,. This method with some modifications has stood the test of time and has largely overcome the problems of the conventional clinical examinations mentioned earlier. Recently, the method was the subject of an international conference at Ottawa in 1985 when the worldwide experiences with OSCE and OSPE were exchanged.
Unfortunately, the method is still used very rarely and that too only for formative evaluation in our country except for the AIIMS, New Delhi, where it forms part of the summative evaluation for students. The purpose of this presentation is to introduce OSCE and OSPE both as an evaluation and a teaching tool and to draw attention to its advantages and disadvantages.
OSCE is an assessment tool in which the components of clinical competence such as history taking, physical examination, simple procedures, interpretation of lab results, patient management problems, communication, attitude etc. are tested using agreed check lists and rotating the student round a number of stations some which have observers with cheek lists.
The OSCE examination consists of about 15-20 stations each of which requires about 4-5 minutes of time. All stations should be capable of being completed in the same time. The students are rotated through all stations and have to move to the next station at the signal. Since the stations are generally independent students can start at any of the procedure stations and complete the cycle. Thus, using 15 stations of 4 minutes each, 15 students can complete the examination within 1 hour.
Each station is designed to test a component of clinical competence. At some stations called the procedure stations students are given tasks to perform on patients. At all such stations there are observers with agreed check lists to score the student's performance. At other stations called "response stations", students respond to questions of the objective type or interpret data or record their findings of the previous procedure station.
Example of a procedure station
Task - Examine the scrotal swelling in this patient.
Points in the check list:
1. Does he explain to the patient what he is going to do?
2. Does he take permission *7
3. Does he provide a screen?
4. Does he ask the patient to expose the whole abdomen and genitalia?
5. Does he examine both sides of the scrotum?
6. Does he take care not to cause discomfort?
7. Does he palpate the spermatic cord?
8. Does he palpate the abdomen (for lymphnodes in case it is a patient with a testicular tumour)
9. Does he palpate the supraclavicular nodes?
10. Does he thank the patient?
Weightage for each item in the check list can be decided by the examiners depending on their importance. Points 1, 3, 6, 10 test the affective domain which is not usually tested by the clinical examination.
Example of an OSPE
Task - Examine the specimen of urine provided for proteins.
1. Does he take a urine sample to 2/3 level in the test tube?
2. Does he boil upper 1/3 of the column?
3. Does he add 2% acetic acid drop by drop?
4. Does he compare change in the top layer with the bottom layer of urine?
Similarly, OSCEs and OSPEs can be made for any subject. At the end of the examination, the scores obtained in the procedure stations are totalled to give the candidate score. Scores at individual stations can also be released to give the candidate a meaningful feedback.
Features of OSCE
In summary, therefore, the main features of OSCE/OSPE is that both the process and the product are tested giving importance to individual competencies. The examination covers a broad range of clinical skills much wider than a conventional examination. The scoring is objective, since standards of competence are preset and agreed check lists are used for scoring. Where questions are asked in response stations, these are always objective. Simulations can be used for acute cases and there is scope for immediate feedback. Patient variablility and examiner variability are eliminated thus increasing the validity of the examination.
Advantages of OSCE / OSPE
In addition to the above points, OSCE ensures integration of teaching and evaluation. Variety maintains student's interest. There is increased faculty-student interaction. OSCE is adaptable to local needs. A large number of students can be tested within a relatively short time.
The process is, however, not without limitations. There is risk of observer fatigue if the observer has to record the performance of several candidates on lengthy check lists. All stations must invariably demand only equal time. Ensuring this, therefore, requires careful organisation. Also, it is considered by many that breaking clinical skills into individual competencies is artificial and not meaningful.
Over the years, increasing experience with the procedure has led to the use of OSCE not merely as an evaluation tool but as a teaching method. This has largely been attributable to the feedback that OSCE gives both students and teachers as exemplified in the following situation.
The task assigned to the candidate was 1o examine for clubbing". The points in the check list were:
1. Does he see the nail profile?
2. Does he palpate for fluctuation?
3. Does he compare both hands?
4. Does he examine the toes?
5. Does he interpret correctly?
In one test, although more than 93% of students got points 1 and 5 correctly, 45-50% got points 2 and 3 correctly and only 25% got point 4 correctly. This feedback to the teachers is very useful in emphasising the fact that clubbing may involve only one hand, only the toes or that palpation is as important as inspection. In a conventional clinical situation, 93% of students would have observed that clubbing was present and got full credit although they had not palpated for fluctuation or examined the opposite hand or the feet.
In conclusion, OSCE/OSPE has several distinct advantages. However, in the current situation it may not be realistic to expect its inclusion in the formal summative evaluation schedule of universities. However, it is feasible in view of the tremendous advantages that it offers, to include the formative (day to day) assessment of students to improve their clinical competence and to derive an objective score for internal assessment.