Tips for Prescribing Safety Assessment (PSA)

The Prescribing Safety Assessment (PSA) is an internet-based examination taken by students in UK medical schools during the final year. I took the PSA on 1 February 2019 and managed to pass it with a score of 72%, while the pass threshold was 63%. I took the PSA again on 3 February 2020 and managed to pass it with a score of 87%, while the pass threshold was 61%. I completed my MBBS course at NUMed and subsequently worked as a Teaching Fellow there. Here, I would like to share some tips for passing the PSA. These tips are intended for all medical students who are taking or retaking the PSA.


General tips

- You have to start your revision no less than 1 month before the PSA. I recommend spending at least 3 hours per day during weekdays and 6 hours per day during weekends and holidays on the PSA.
- If your medical school provides teaching or practice sessions for the PSA, you should attend them. Be sure to engage well with the sessions. If you don't understand anything, ask your lecturer or friends.
- The recommended reference books for the PSA are Pass The PSA, Get Ahead! The Prescribing Safety Assessment, MasterPass Student Success in the Prescribing Safety Assessment, Oxford Handbook of Clinical Medicine (10th Edition), Oxford Handbook of Clinical Specialties (10th Edition) and the textbooks for the specialties. Note that the questions in the MasterPass Student Success in the Prescribing Safety Assessment book are not well aligned with the PSA format, but it's still useful to do them as a practice.
- It is important that you do PSA practice questions to familiarise yourself with the question style and format. Complete all practice papers on the PSA website and all questions in Pass The PSA, Get Ahead! The Prescribing Safety Assessment and MasterPass Student Success in the Prescribing Safety Assessment. You should also do the practice questions that are provided by your medical school. You can find more practice questions on the Internet. Prepare for the PSA has free questions while Passmedicine and Pastest require paid subscription.
- Time yourself when doing the practice questions and always try to finish them within the time limit. This is because the amount of time provided to answer the PSA is rather short.
- After finishing the practice questions, find out if your answer for each question is correct. You should understand the reasoning behind every correct or wrong answer.
- You must be familiar with using the online version of the BNF. Ensure that you are able to find any information you need in it quickly. You can press Ctrl+F to locate a particular word or phrase in a web page. For all questions with a paediatric setting, you should use the BNFc instead of the standard BNF. The online version of BNF is usually preferred over the paper copy of BNF. However, certain information may be easier to find using the paper copy of BNF, so it is good to familiarise yourself with it too.
- You should treat the PSA like the final examinations of your medical school. You need to revise your clinical knowledge for the PSA as not all information is available in the BNF. This also reduces the need to refer to the BNF during the PSA, which saves time.
- Start by revising all the notes in Pass The PSA and Get Ahead! The Prescribing Safety Assessment. If you have lecture slides or notes from the PSA teaching sessions of your medical school, revise them as well.
- After that, revise all important conditions in the Oxford Handbook of Clinical Medicine, Oxford Handbook of Clinical Specialties and the textbooks for the specialties. Your main focus should be on pharmacological management, but diagnosis, investigations and non-pharmacological management are important too.
- You should also revise the fluid management, opioid pain management, insulin management and pre-operative management topics in the Oxford Handbook of Clinical Medicine. Questions on these topics are common in the PSA and many find them difficult. Fluid management is particularly important.
- You need to know the management guidelines for the more common conditions. Important guidelines are those that can be found in the books, and you should look up the internet for the most up-to-date version of those guidelines. Some guidelines are available in the BNF.
- Your revision should be done through understanding rather than memorising. For every fact you come across, try to either seek an explanation or come up with your own explanation. Even a wrong explanation is usually alright as the PSA won't test on the explanation. This helps you remember the fact much better compared to simply memorising.
- However, there are still certain facts that are difficult to be studied by understanding as they have no possible explanation at all. For such a fact, you should check whether or not the BNF has information on it. If it is not in the BNF, you have to memorise it.
- Do not memorise the normal range of values for investigations as it will be provided in the PSA questions. Do not memorise the doses of drugs apart from very commonly used drugs as that information can be found easily in the BNF.
- To ensure that you do not forget what you have revised for the PSA, you should do several rounds of revision. You should also look back at the practice questions that you have done as well as the answers.
- The PSA is becoming more difficult from year to year. The questions in the actual PSA are generally more difficult compared to the practice papers on the PSA website. The pass threshold of the PSA is usually somewhere between 60% and 65%.
- When taking the actual PSA, you should bring in a scientific calculator. Although the PSA website has a calculator, a real scientific calculator is easier to use and has more functions. You should also bring in paper copies of the latest versions of BNF and BNFc if they are not provided by your medical school, in case you want to use them.
- You are advised to spend no more than 4 minutes for each question in the Prescribing section, no more than 3 minutes for each question in the Prescription Review section and no more than 85 seconds for each question in all other sections.
- The questions in the Planning Management, Providing Information, Adverse Drug Reactions, Drug Monitoring and Data Interpretation sections are in the Single Best Answer (SBA) format. For each question, there are 5 choices of answers where you have to choose the one that is the most appropriate.
- With the exception of the Prescribing and Prescription Review sections, each question in all other sections carries 2 marks. A correct answer scores 2 marks while an incorrect answer scores 0 mark, there is no in-between.


Section 1: Prescribing

- This section alone carries 40% of the total marks and is therefore the most important section in the PSA. You should attempt this section first and try your best to score well in it.
- Each question carries 10 marks, where 5 marks are for the drug choice and 5 marks are for the dose, route & frequency. A perfect answer scores 5 marks, a suboptimal answer scores between 1 to 4 marks, while a wrong answer scores 0 mark. Note that the mark you get for dose, route & frequency cannot be higher than the mark you get for drug choice.
- Starting from 2020, marks are no longer given for the date, time & signature, and you are not required to enter them in each question. This makes it more difficult to score well in this section.
- For each question, there will be a clinical case and you will be given one of the following: once-only medicines prescription chart, regular medicines prescription chart, general practice prescription form or hospital fluid prescription chart.
- In some cases, the question will tell you the diagnosis, while in other cases, you have to determine the diagnosis based on the information given. The BNF won't usually help you in determining the diagnosis, so your clinical knowledge and judgement is needed.
- Based on the diagnosis, you have to prescribe one drug or fluid that is the most appropriate. Sometimes, the question specifically requires you to prescribe a drug to achieve a particular effect.
- Use your clinical knowledge and judgement to determine the most suitable drug or fluid, taking into consideration all information provided in the question. You can also refer to the BNF for guidance if needed, though not all information is available in the BNF.
- You must make sure that there are no contraindications or allergies to any drug you want to prescribe. The list of contraindications of each drug is available in the BNF. Prescribing a drug that is contraindicated will likely cause you to score 0 mark for the whole question.
- In some cases, a particular drug may be very helpful or important in the management of the diagnosed condition, but it does not help in achieving the effect that the question specifically asks for. Do not prescribe such a drug, otherwise you may score 0 mark for the whole question.
- If the question states that the patient in the case does not want a particular type or form of drug, you should avoid prescribing that if possible. If you still prescribe it, you will not be able to score full marks.
- You are able to prescribe only one drug for each question. In the case where more than one drugs can be prescribed, some of them may be contraindicated which you definitely should not prescribe. It is also possible that more than one drugs are equally good and you can score full marks for that question by prescribing any one of them.
- After you prescribe a drug, you have to state the dose and route of administration. For regular medicines and general practice prescriptions, you also have to state the frequency. You need not state the duration. Refer to the BNF for the correct dose, route and frequency under the right indication.
- For fluid prescriptions, you have to state the volume and duration. Information on the correct volume and duration is not usually available in the BNF, so this requires your clinical knowledge and judgement.
- In most cases, you should prescribe a drug using its generic name, unless if only its brand name is the approved name. Do not prescribe any non-pharmacological treatment.


Section 2: Prescription Review

- In this section, each question will list several drugs that have been prescribed, where you have to identify one or more of the drugs that are inappropriate or have a particular problem, such as adverse effects, contraindications, interactions with other drugs, ineffectiveness or dose error.
- Most of the questions can be answered with the help of the BNF. However, as there are several drugs listed in each question, having to look up every one of them in the BNF will require a lot of time. To save time, your clinical knowledge is important. Refer to the BNF only if you are unsure.
- You can press Ctrl+F on the online version of the BNF to quickly search for a particular word or phrase, such as an adverse effect or a contraindication. Note that there may be a few different wordings for a particular adverse effect and the BNF will only use one of them. Also note that drug interactions are listed in a separate page linked from the page of each drug.
- There are certain adverse effects and drug interactions that are commonly asked in this section. Try to take note of them when doing practice questions and remember the common drugs involved.
- When identifying drugs with dose errors, note that in some cases the error is with the frequency rather than the dose itself. A correct dose with a wrong frequency counts as a dose error as well.
- When identifying drugs that are causing an adverse effect, you may sometimes find that the number of drugs that could be causing the effect is greater than the number of drugs that the question is asking for. In this case, you should take into consideration how commonly each drug causes the adverse effect and when the drug was started relative to when the adverse effect developed. If everything seems equal, then you should exclude from your answer the drug that is less likely to cause the adverse effect based on your own understanding of its pharmacology.


Section 3: Planning Management

- In this section, each question will contain a clinical scenario and you will be asked how to manage the patient.
- In some cases, the question will tell you the diagnosis, while in other cases, you have to determine the diagnosis based on the information given.
- You have to determine the immediate next step of management that is most appropriate, based on the diagnosis. It may be pharmacological or non-pharmacological management, and you should consider both equally.
- Use your clinical knowledge and judgement to determine the most suitable management from the 5 choices of answers, taking into consideration all information provided in the question. The BNF may be able to help, but only in some cases.
- For acute conditions, ABCDE is usually the first step of management. If there is an answer choice involving ABCDE, it should be the answer.
- For pharmacological management, the dose, route of administration, frequency and duration of each drug in the choices of answers may or may not be correct, so you need to think about them as well. These information are available in the BNF, though not usually for fluid management. Even if among the 5 choices there is only one drug with one dose, route, frequency and duration, do not assume that everything is correct for that drug.
- There may be more than one correct management options, but one will be better than the others. Ensure that there are no contraindications to a particular management option before selecting it. You can look up the BNF for the contraindications of each drug.


Section 4: Providing Information

- Each question in this section will consist of a scenario where a patient is being prescribed a particular drug and you will be asked to decide on what information should be communicated to the patient.
- Among the 5 choices of answers, there may be more than one with correct information, but only one contains the information that is most appropriate to tell the patient.
- For certain drugs, there is a 'Patient and carer advice' section in the BNF. You should check and see if it is there. The information under that section is usually the most appropriate information for the patient and therefore is the answer.
- If that section is not there, then you should start by identifying the answer choices with correct information and eliminating those with wrong information, using your clinical knowledge. The BNF is often helpful in this, but you will waste time if you look it up for every one of the choices. Then, you have to use your judgement to determine which of the correct information is the most appropriate to be given to the patient.
- Generally, information that is directly related to the safety and effectiveness of the drug should be given priority.
- It is common for this section to have a question about giving advice regarding missed oral contraceptive pills. The full advice is available in the BNF, but it may be difficult to locate. You need not remember the advice, but you must be very sure where to find it in the BNF. Practise finding it beforehand.


Section 5: Calculation Skills

- This section contains calculation questions where you have to calculate the dose, volume or rate of administration of drugs. It is the easiest section to score full marks, as long as you don't make careless mistakes.
- This section requires basic mathematical skills that you learnt back in primary and secondary school, not more than that. You may have forgotten them, but doing a lot of practice questions is a good way to brush up your mathematical skills.
- You may notice that some of the practice questions for this section require using the BNF or clinical knowledge. However, the questions for this section in the actual PSA will not require them, it is purely calculation.
- Usually, only some of the information given in the question are relevant to the calculation. However, you should still read all the information to ensure that you don't miss anything important.
- The calculation may involve several steps of addition, subtraction, multiplication or division. Use a calculator to perform the calculations. A real scientific calculator is preferred over the calculator on the PSA website.You can write down the calculation steps on a piece of paper if it helps.
- It's important to know and remember the following:
1 g is equivalent to 1 mL or 1 cc, while 1 kg is equivalent to 1 L.
1% of a solution can mean 1 g in 100 mL, 100 mg in 10 mL or 10 mg in 1 mL.
0.1% of a solution can mean 100 mg in 100 mL, 10 mg in 10 mL or 1 mg in 1 mL.
1000 mL = 1 L, 1 mL = 1 cc
1000 nanogram = 1 microgram, 1000 microgram = 1 mg, 1000 mg = 1 g, 1000 g = 1 kg
- Pay attention to the frequency and duration of the prescriptions in the question. The question may require you to perform some calculations on that.
- The unit of the final answer is usually provided by the question. Make sure that your final answer is in that unit. If the question states that you have to round your final answer to a specific number of decimal places or to the nearest whole number, you have to follow that instruction.
- In some cases, it may be a common clinical practice to round certain doses or volumes to a certain nearest value. However, you should not round your final answer unless you are instructed by the question to do so.
- When entering your final answer, do not include any of your calculation steps. After you got your final answer, it is good to recheck it by performing the whole calculation once more.


Section 6: Adverse Drug Reactions

- There are 4 types of questions in this section. The first is identifying the adverse effect caused by a specific drug, the second is identifying the drug that is causing a specific adverse effect, the third is identifying drug interactions and the fourth is managing an adverse drug reaction.
- The first, second and third types of questions can usually be answered with the help of the BNF, while the fourth type of question usually requires your clinical knowledge and judgement.
- You can press Ctrl+F on the online version of the BNF to quickly search for a particular adverse effect of a drug. Note that there may be a few different wordings for a particular adverse effect and only one will be used in the BNF.
- On the online version of the BNF, there is a link in the page of each drug that takes you to another page that lists the drug interactions. You need to go to that page and press Ctrl+F there if you are searching for a particular drug interaction.
- For the first, second and third types of questions, you may sometimes find that more than one of the answer choices could be the correct answer. In this case, you should take into consideration how common each adverse effect or drug interaction is. If they seem equally common, then you should exclude the answer choice that is less likely based on your own understanding of the drugs' pharmacology.
- For the fourth type of question, you have to determine the immediate next step of management that is most appropriate for the adverse drug reaction. It may be pharmacological or non-pharmacological management. The BNF may be able to help, but only in some cases.
- ABCDE is usually the first step of management for adverse drug reactions. If there is an answer choice involving ABCDE, it should be the answer. For pharmacological management, the dose, route of administration, frequency and duration of each drug in the choices of answers may or may not be correct, so you need to think about them as well. These information should be available in the BNF.
- Anaphylaxis is an adverse drug effect commonly tested in the PSA, so you have to know its management well.
- Questions about managing haemorrhage caused by oral anticoagulants are common in the PSA. The full management guideline is available in the BNF so you need not memorise it, but you must know where to find it in the BNF.


Section 7: Drug Monitoring

- Each question in this section will consist of a clinical scenario where you will be asked to plan the monitoring of a drug being prescribed.
- The question may ask you what is the monitoring required before starting the drug or how to monitor for beneficial effects or adverse effects after starting the drug.
- Among the 5 choices of answers, there may be more than one correct monitoring options, but only one is the most appropriate.
- There is a 'Monitoring requirements' section in the BNF for many drugs. The information under that section is often the answer for questions about the monitoring required before prescribing a drug as well as questions about the monitoring for adverse effects.
- For questions about the monitoring for beneficial effects, you need to use your clinical knowledge and judgement to determine to most appropriate monitoring option. The information about that is not usually available in the BNF.
- Generally, the most appropriate monitoring is one which its results correlates closely with, responds quickly to and is specific to the improvement brought about by the drug. It may in the form of investigations or monitoring of clinical signs or symptoms.
- For a patient being given oxygen, the most appropriate monitoring is arterial blood gas (ABG) while the second best monitoring is pulse oximetry (SpO2). For a patient being given fluids, the best monitoring is blood pressure while the second best monitoring is urine output. Remember these.


Section 8: Data Interpretation

- For each question in this section, there will be a clinical scenario with results of investigations and you have to make a change to the drug prescriptions. The investigations may include plasma drug concentration.
- Based on the information provided, you have to decide whether to stop a drug, decrease the dose, increase the dose, prescribe another drug or make no changes.
- You have to choose the most appropriate answer from the 5 choices of answers, using your clinical knowledge and judgement. The BNF may be able to help, but only in some cases.
- Generally, you should take into consideration the plasma drug concentration, response to the drug and features of toxicity. If the plasma concentration is below normal range and the response is inadequate, then increase the dose, usually by the smallest increment among the answer choices. If the response is adequate but the plasma concentration is below normal, do not change the dose.
- Meanwhile, if the there are clinical features of toxicity, stop the drug temporarily and treat the toxicity, then either restart it at a lower dose or switch to another drug. If the plasma concentration is above normal but there are no features of toxicity, then decrease the dose. The required percentage of reduction in the dose is usually the same as the percentage of reduction in the plasma concentration that you want to achieve.
- If the peak concentration of a drug is outside normal range, you should adjust the dose. If the trough concentration is outside normal range, you should adjust the interval between doses.
- For insulin, each time its dose is adjusted, the adjustment is usually 10% of the original dose.
- It is common for there to be paracetamol or gentamicin nomogram in this section. Make sure that you know how to interpret them.

Tips for the UKMLA AKT and PLAB 1 can be found here:

https://daniellimjj.blogspot.com/2023/03/tips-for-ukmla-akt.html