Chapter 1 How to approach an OSCE: clinical stations
INTRODUCTION
An ‘Objective Structured Clinical Examination’ (OSCE) is a short, simulated clinical scenario designed to assess the clinical skills of the examination candidate. This method of examination was first proposed in 1975 by R.M. Harden as one way of providing ‘a more objective approach to the assessment of clinical competence’.
In an OSCE examination candidates move through a number of short clinical scenarios which are designed to focus on a range of topics and specific clinical skills. This can be contrasted with the traditional clinical examination – the ‘long case’ – where the candidate would take a history and examine a patient in private, before presenting examiners with the findings, proposed diagnoses, required investigations and treatment. In his original article, Harden found that the OSCE results had a far better correlation with the written results of the students than the traditional approach as the patient (usually simulated) was the same for all students, while the examiners had a standard marking sheet, making their assessment both clear and reproducible.
Since its introduction the OSCE has become a widely used examination tool for both undergraduate medical student and postgraduate specialist examinations. It is currently a key component of the examination process in Obstetrics and Gynaecology at our institution. While it does not replace the need for written examinations to test purely factual knowledge, it does assess a different range of skills that are of a more practical nature.
Aspects of clinical practice that can be assessed in an OSCE range from taking a patient’s general history and asking questions appropriate to the presenting complaint to taking a focused history on a particular problem (such as a menstrual history or a sexual history), explaining investigation results in terms that a patient can understand (e.g. an abnormal fetal ultrasound result or an abnormal Pap smear), performing a specific clinical examination (e.g. a routine newborn examination) or acting out a clinical ‘action’ such as taking a Pap smear, performing neonatal resuscitation or dealing with a shoulder dystocia in labour.
Medical students
There is often a lot of concern surrounding the OSCEs by medical students as they are less familiar with the format than they are with written examinations, a familiar format first experienced at secondary school. The techniques of history-taking, examination, and counselling and talking to patients are relatively new to them. Nonetheless, these skills are just as important to their future success as doctors as the factual knowledge they gain from reading the textbooks.
MRANZCOG candidates
Candidates for the specialist entry MRANZCOG (Membership of the Royal Australian and New Zealand College of Obstetrics and Gynacology) exam may be more comfortable with history-taking, examining and counselling patients, but less familiar with the OSCE examination process. While the exams aim to mimic clinical practice, there is a certain ‘knack’ to passing them which requires an understanding of their format and how they are assessed.
The importance of practice
The old saying that ‘repetition is the mother of learning’ is no less true of OSCEs than it is of any other examination type. There is no doubt that the more practice cases and scenarios candidates experience, the more likely they are to pass the exam. This textbook has been written with the aim of providing a significant number of practice cases, together with a detailed marking scheme, so that exam candidates working in pairs will be able to assess each other objectively and improve their performance by reviewing ideal answers. Not all examination candidates manage to obtain enough practice before the OSCE exam, and the preparation of cases by ‘practice’ examiners is time-consuming, meaning that busy doctors are often unable to provide adequate time to go through practice cases. We hope that this book will allow candidates for an OSCE in Obstetrics and Gynaecology, either at undergraduate or postgraduate level, to gain sufficient practice before the exam to maximise their chances of a pass.
BASIC OSCE STRUCTURE
Medical students
The basic structure of OSCEs for medical students may vary from institution to institution, and you should check with your faculty to see what your institution expects. At our university OSCEs are usually made up of 1 minute reading time, followed by 6 minutes with the examiner, often with an actor playing the role of the patient. After the first 5 minutes (i.e. after 6 minutes of the 7-minute station), the examiner is required to give an indication to the candidate that only 1 minute remains before the end of the OSCE station. At the end of the 7 minutes a bell is sounded and the examination candidate must move on to the next station.
MRANZCOG candidates
The MRANZCOG OSCEs have a uniform format for all candidates. At present the OSCEs are 20 minutes in total, with 5 minutes reading time at the start of the station, followed by 15 minutes with the examiner. Obviously these OSCEs are more complex than the cases for the medical students, and the candidates often have three to five scenarios to go through, which test a wide range of both obstetric and gynaecological knowledge before they can proceed to the next station. Generally at the first station the candidate takes a detailed history from the simulated patient (either an actor or the examiner playing the role of the patient and answering questions).
Marking
The OSCE examiner usually has a marking sheet with a set of marks assigned to key clinical points – either specific questions relating to history, examinations performed, differential diagnoses, or information on prognosis or implications for the patient’s health imparted to the patient. This rather rigid marking scheme means that marks can be gained only for the specific points indicated. However, it does ensure a uniform marking scheme for all examination candidates, allowing for the marks of two candidates to be directly compared.
One problem that arises with this marking scheme is that some candidates demonstrate more orderly and logical thought processes in the way that they direct history-taking, examination and investigation of the patient than others. Therefore, some OSCEs will have a proportion of marks assigned to ‘clinical competency’ (e.g. 5 out of 20 marks), so that well-organised candidates have the opportunity to distinguish themselves.
Reading time
Reading time is an integral part of the OSCE, and it is very important to use this time wisely. It is even more important in the MRANZCOG OSCE, as there are 5 minutes assigned, rather than the 1 minute allocated for the medical student OSCE. The amount to be ‘read’ may only amount to one or two sentences, but there is important information in those few short lines. The introductory information may be presented, for example, as a letter from a referring general practitioner, or as a short clinical description.
Extracting maximum information from the introduction
EXAMPLE: Mrs Bloggs is a 41- year-old G3 P2 at 8/40 gestation presenting for her first antenatal visit.
This introduction has already given us a number of pieces of important information. First, the patient’s age – she is 41 years old and of advanced maternal age. She will need to be counselled about the increased risk of miscarriage (due to aneuploidy), gestational diabetes in pregnancy (she will need a glucose tolerance test rather than just a glucose challenge test at 28/40), pre-eclampsia and Down syndrome (one in 100 risk – need to discuss screening/amniocentesis/chorionic villous sampling).
Second, she has had two previous deliveries of greater than 20 weeks gestation. We will need to ask about the mode of delivery, the gestation at delivery and any previous pregnancy, delivery (e.g. shoulder dystocia), or post-delivery problems (e.g. post-partum haemorrhage, breastfeeding problems, Group-B streptococcal infections in the neonates). All of these pieces of information may impact on our management of the pregnancy.
Third, the patient is at 8 weeks gestation, so issues to be encountered are likely to occur, at least initially, in the first trimester. We will need to ask about early pregnancy problems (e.g. bleeding, pain, hyperemesis gravidarum, urinary problems). Finally, we are told that the patient is presenting for her first antenatal visit, so we will need to order and explain all of the routine antenatal screening (FBE, blood group and antibodies, rubella IgG levels, hepatitis B serology, RPR or other test for syphilis, offer HIV testing, midstream urine for culture, and possibly a first trimester ultrasound for dating the pregnancy).
Most of the introductory scenarios will similarly have information to be gleaned to a greater or lesser degree (see the boxed text below for common clinical points from the introductory statement). Use the reading time to jot down as much of the information or relevant history and examination details as you can, so that you remember it. It is easy to forget a seemingly minor detail that becomes very important to the scenario later on.
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