The prescribing process and evidence-based medicine
Good prescribing ensures maximum benefit for the patient and value for money
Introduction
The prescribing of medicines is the most common medical intervention in patient care and drug costs are a major component of NHS expenditure. Ensuring optimum benefits for patients and value for money for taxpayers and other individuals and organizations paying for health care are priorities and a model of ‘good prescribing’ has been proposed that has four aims. These aims are to:
Maximizing effectiveness is about selecting a drug therapy that will achieve its therapeutic objective in a suitable timescale.
Minimizing risks is recognizing that all drug treatments carry an element of risk of causing harm to the patient and that selection of the drug should be about managing these benefits and risks.
The cost of therapy should also be taken into account by the prescriber although such consideration should go beyond a simple review of the drug costs but also consider any costs of monitoring treatment such as blood tests, length of treatment and any additional items that could be required such as prescribing an additional drug to protect the gastrointestinal tract from adverse effects caused by the first.
Establishing the views of the patient is a vital part of the process of assessing the relative importance of the first three aims in this model. Patients may differ in their views regarding managing the symptoms of a condition, living with the consequences of a condition, exposing themselves to risks of harmful effects and the amount of money they would be willing or able to pay for treatment. In addition, patients may wish product selection to take their lifestyle into account such that the frequency and route of administration of the selected product fits in with their daily routine.
It is accepted that ‘good prescribing’ involves trade-offs between these four aims and that this often involves delicate balancing between each of the aims.
The prescribing process
The prescribing process will be considered under five headings although there is some overlap between these and their sequence may not be the same in all cases. The first is concerned with all the things that must be in place before a prescriber can start to prescribe; the second with collecting information; the third with analysing the information and making the prescribing decision and the fourth with making appropriate records and plans for monitoring the patients progress and the last with auditing and evaluating prescribing practice.
Prerequisites
Prescribing can only be carried out by healthcare professionals that have the appropriate prescribing qualifications and these will vary depending on the type of prescribing to be carried out. To prescribe prescription only medicines on the NHS or privately the prescriber, if not a medical prescriber, must have successfully completed the training to allow them to act as a supplementary or an independent prescriber. The training course consists of a taught element (around 26 days) and learning in practice (around 12 days), which includes prescribing under the supervision of a medical prescriber. To participate in a minor ailment scheme and prescribe pharmacy only medicines at NHS expense the pharmacist will likely have had to complete appropriate accreditation set by the local primary care organization.
Patients that are to receive their prescriptions from a supplementary prescriber must give informed consent. Patients do not need to sign this informed consent but is good practice to make a note in the patient’s medical notes when informed consent was given. The exact nature of informed consent is difficult to define and it is likely that the input from the healthcare professional will vary between patients when obtaining consent. Observation of disputes between patients and physicians regarding whether informed consent was given show that simply handing the patient a leaflet does not discharge the physician from their obligation to obtain informed consent. In any legal dispute it is up to the courts to decide which party they believe but the disputes that found in favour of the physician tended to be those where the physician was able to demonstrate that they had given the information to the patient because they had documented the advice they gave in the patient’s medical records.
Prior to the patient consultation, the prescriber should ensure that they are suitably prepared. Part of this preparation includes ensuring they have sufficient indemnity insurance that covers their prescribing and that their job description clearly shows that prescribing is part of their role. Another part of the preparation is acquiring the appropriate knowledge and skills (see Table 20.1).
Table 20.1
Checklist for knowledge and skills required by pharmacist prescribers
| Legal restrictions effecting which medicines can be prescribed | Independent pharmacist prescribers can prescribe any licensed or unlicensed medicine except diamorphine, dipipanone or cocaine for treating addiction but may prescribe those drugs when treating organic disease or injury. Supplementary prescribers can prescribe any licensed or unlicensed medicine including controlled drugs provided it has been specified in the clinical management plan. |
| Professional restrictions effecting which medicines can be prescribed | It is vital that each prescriber only prescribes within their own area of competence. Knowing one’s own limitations is a key skill for a prescriber. In addition, they must also have an appropriate level of experience dealing with the condition and it might be appropriate to refer a patient presenting with a condition rarely experienced to another prescriber for assessment and any prescribing if required. |
| Administrative arrangements regarding payments for the service | The administrative arrangements regarding the prescribing process must be fully understood. In the case of minor ailments schemes these arrangements could include a description of records that should be kept and how payment for the service is to be made. For NHS prescribing the prescriber should be aware of the categories of patient that are exempt from NHS charges and what payments should be made by those that are not exempt. |
| Patient confidentiality | Pharmacist prescribers must maintain patient confidentiality and take steps to ensure that no unauthorized personnel can gain access to patient medication records by securely storing the data either via lock and key or via appropriate electronic security measures such as passwords for data stored electronically. |
| Ethics | Prescribers should be aware of the good practice guidance from the DH and the GPhC before they start to prescribe. The DH guidance addresses prescribers not prescribing for themselves, not normally prescribing for members of their family and also covers accepting gifts and hospitality for suppliers. Pharmacist prescribers must also comply with the GPhC Standards of conduct, ethics and performance. |
| Security | Prescribers must be aware of security issues surrounding prescribing and take steps to minimize the risks. Blank prescription forms could be used by drug misusers to try and obtain supplies of prescription medicines for abuse or to sell to others. Care must be taken to ensure that the forms are securely stored. Personal security must also be considered if the prescriber is visiting patients in their own homes or other locations in the community. |
| Therapeutic management of conditions | A pharmacist’s knowledge and skills required for the management of a therapeutic area must be up to date and based upon the best evidence available at the time. The knowledge should extend to non-drug approaches to treatment as sometimes these could be the most appropriate intervention. |
| Other members of the healthcare team | Prescribers should be aware of other professionals they could refer patients to, e.g. general practitioner, the accident and emergency department in the hospital, dentists, the community nursing service (district nurses and health visitors) social services and self help groups. |
Consulting with the patient
Where possible, prescribers should also familiarize themselves with the patient’s medical history prior to the consultation. This however, would not be possible in minor ailment schemes, as patients are likely to arrive without an appointment and their medical notes will not usually be available to the community pharmacist.
During the consultation, prescribers must take a full history of the presenting condition and any other factors such as other conditions the patient have or any other medications including OTC medicines and complementary medicines that the patient may be taking. It may be necessary to carry out further investigations such as measuring the patient’s blood pressure. This information must be recorded in the patient’s medical notes.
Before any prescribing can take place a diagnosis must be made. If the pharmacist is acting as a supplementary prescriber the diagnosis will have been made by an independent prescriber but the pharmacist should interpret the information obtained before and during the consultation to check that patient’s diagnosis remains valid. Independent prescribers must establish a working diagnosis based upon the information they have gathered on the patient. At this stage, it may be necessary to request laboratory tests such as urea and electrolytes, red blood cell count and haemoglobin tests to help confirm the working diagnosis.
With increasing complexity of health care and increasing specialization of the roles of healthcare professionals, there is a growing need for different professions to work together and pharmacists must ensure that they are aware of the different professions they could call on for support or to refer to patients (see Table 20.1).
Where patient care is shared between healthcare professionals there is an obvious need for clear communication links, especially around monitoring and reviewing the patient’s therapy. Clear communication links are particularly crucial in supplementary prescribing where two different professionals can prescribe for a patient. There must be a clear description of the criteria that would require the supplementary prescriber having to refer the patient back to the independent prescriber. Examples of such referrals could be failure of the patient’s condition to respond to the therapy outlined in the clinical management plan or suffering an adverse reaction to the prescribed medication. Both independent and supplementary prescribers must have access to a common medical record.
Prescribing decision-making
Upon analysis and interpretation of the patient’s signs, symptoms and laboratory test results, the prescriber must consider the treatment options including the option of offering no treatment to the patient. The consideration of therapy options must include concurrent diseases and concurrent medication, the patient’s lifestyle (would the treatment regime fit in with the patient’s schedule or would side-effects of drugs affect their ability to perform their usual activities, e.g. driving).
A key component of this phase is involving the patient in the decision-making in order to achieve concordance (see Ch. 18). The prescriber must communicate the benefits and risks of the different treatment options to the patient or their carer. The principles of concordance dictate that patients should fully participate in the decision making process and a consultation style where patients are treated as equals and have the opportunity to ask questions and to raise any concerns or worries they might have helps to achieve this.
Following selection of the drug and formulation, the dosage regime must be determined. The dosage guidance in the summary of product characteristics, BNF or local and national clinical guidelines should be used to work out the dosage to be prescribed. In general it is recommended that dosage be started at the lower end of the dosing schedule and that the dose should be gradually increased until the required therapeutic benefits are seen and side effects are minimized. However, there are many exceptions to this such as prescribing a loading dose for certain antibiotics or prescribing drugs where the therapeutic benefits are not obvious such as drugs used in prophylaxis.
The prescriber must also indicate the quantity to be supplied on the prescription. The quantity to be supplied will depend upon whether the treatment is likely to be acute or chronic. If the treatment is acute then the quantity is likely to be enough for the recommended course of treatment. When determining the quantity to be supplied for a chronic condition the prescriber should bear in mind the frequency that they would wish to review the patient, whether the patient has to pay for the item, the patient’s ability to pay the prescription levy and whether there are any dangers from accidental or deliberate overdose. In general, smaller quantities offer the opportunity to review patient’s therapy more frequently and reduce waste if patients are unable to take their medicine through the occurrence of troublesome side effects or adverse drug reactions. However, smaller quantities can cause greater patient inconvenience as patients will to visit healthcare professional more frequently and greater expense if they have to pay for their medication, as well as increasing the prescriber’s workload.
Recording and monitoring
It is important to realize that the responsibilities of the prescriber do not end with signing the prescription. The prescriber must make appropriate records of the medicine(s) prescribed and any advice given to the patient in the patient’s medical notes. For paper held records the prescriber will obviously have to write the name of the prescribed item, the formulation, the strength, dosage instructions in the notes. In the case of electronic prescribing the details of what was prescribed, the date of prescribing and the directions will be stored automatically in the patient’s records. However there may be a need to record additional information such as when the patient should next be reviewed and the monitoring that is recommended.
All prescribing should be followed-up with some monitoring although in some cases this may be left to the patient or carer to do themselves (see Ch. 51). Monitoring should address the anticipated benefits from therapy such as ‘are the symptoms being controlled?’ and harmful effects such as ‘is the patient suffering from adverse effects?’. In many situations the patient or their carer will be given advice regarding what to do should the beneficial effects not materialize or if the harmful effects are troublesome, but there may be situations where these are not apparent such as monitoring blood cell counts following administration of a drug known to effect blood cell formation, and patients should be informed when they will next need to have their therapy reviewed.
Prescribers must appreciate any drug can cause an adverse drug reaction but that certain drugs are more likely to cause an ADR. Therefore, they must be aware of the action required if patients suffer from an adverse drug reaction. Minor ADRs that are known to occur with established medicines do not need reporting while serious suspected and actual ADRs for new and established medicines and all ADRs for new medicines should be reported via the yellow card reporting scheme.
Auditing prescribing practice
Prescribing audits involve reviewing prescribing activity against a set of explicit criteria such as a set of local or national clinical guidelines. For example, this could involve reviewing the prescribing for all patients registered with a practice that have a diagnosis of angina and comparing this with the guidance published by NICE. The audit should specify the standard of compliance with the guideline that is expected (e.g. 90% or 100%). If the audit reveals that expected standard of compliance has not been met then there should be a review of practice to identify why the standard has not been met. Prescribers should reflect upon the findings of the review and agree what action is required. The audit should then be repeated to determine whether the action has had an impact on the compliance with the standard. An audit cycle involves repeating the audit, review and action (see Ch. 12).
Evidence-based medicine
Evidence-based medicine (EBM) has been described as ‘a means of closing the gap between research and everyday practice and ensuring that clinical decisions are based upon the best available scientific evidence’. It allows healthcare professionals to compare the evidence for different treatment options. This comparison may sound easy but unfortunately the available evidence is frequently of variable quality, which makes comparisons difficult.
The process of EBM involves four stages. The first involves identifying the question to be answered such as: Does treatment with drug X prevent more cardiovascular events than drug Y? The second stage involves searching the literature to find studies that have compared drug X with drug Y. The third stage is a critical appraisal of the studies that have been identified which involves making judgements about the quality of the studies, comparing the evidence supporting drug X with the evidence supporting drug Y and determining whether the balance of evidence favours one drug over the other. The final stage is about applying the evidence to clinical practice, which could involve recommending one drug be prescribed by clinicians rather than the other.
Assessing the quality of the evidence involves comparing the studies reported in the literature. There is a hierarchy of type of studies in terms of quality with meta-analysis of more than one randomized controlled trial at the top, then single randomized controlled trials, then controlled trials without randomization, then descriptive or case control studies and finally reports from expert committees (see Table 20.2 for a description of these terms). A key point to note concerning the method used in the study, is whether the study was double blind or not (double blind is where the researcher and the subjects did not know which treatments were given to the subjects).
Table 20.2
Descriptions of studies investigating health care
| Type of study | Description |
| Meta-analysis | A statistical method of combining the results of more than one trial |
| Double blind randomized controlled trial (RCT) | A study where one group of subjects was randomly assigned to receive one treatment and the other group to receive an alternative treatment or placebo. Double blind is where neither the researchers nor the subjects are aware which group they have been assigned |
| RCT | A study where one group of subjects was randomly assigned to receive one treatment and the other group to receive an alternative treatment or placebo |
| Case–control studies | A study that compares one group of patients with another |
| Cohort studies | A study that follows the progress of a group of patients (a cohort) and compares their progress to the characteristics of the group members |
| Expert opinion | A report from an expert committee or opinions expressed by a respected group of experts |
The review of a study should also consider whether there is a potential for bias in the study by considering who funded the study and the affiliations of the authors.
It is important to review the doses of drugs used as some studies do not use equivalent doses of drugs particularly where one drug is compared with a competitor’s drug. The reviewers should consider whether the study used healthy volunteers or patients suffering from the condition and whether the demographic profile of the subjects was similar to the general population. Generally, the larger the study in terms of the number of subjects included, the higher the quality of the study but the number of subjects needed to show an effect is dependent on the magnitude of the effect with larger numbers needed to demonstrate smaller differences between the different arms of the study.
The length of the study is another important consideration and this should be related to how the drug will be used in practice as the benefits reported in a study lasting 10 days would have more relevance to a drug used to treat acute short-term conditions compared with long-term chronic conditions, where the benefits could wear off after the study ends. The review should consider the endpoint reported in the study (what was measured in the study) and whether the endpoint was the same as the intended outcome (e.g. the intended outcome of a treatment in a study could be a reduction in the incidence of cardiovascular events but endpoint of the study might just address one risk factor for cardiovascular events).
Information sources
The evolution of modern medicines and appliances has resulted in a tremendous increase in the range of products available on prescription, and a corresponding increase in the amount of information available to support their use. This vast array of information originates from many sources including the pharmaceutical industry, academic institutions, professional bodies, government agencies and patient groups. Much of this information is aimed at prescribers and other professional groups, but with the increased availability of this information through advances in information technology and the upsurge of public demand, many patients also have greater access to information about medicines. With such a variety of sources all competing for the attention of the prescriber there is a danger that they could be overloaded with information of variable quality and which is potentially conflicting (see Ch. 16).
Reports of studies published in the literature can be obtained by using Medline, Embase or Pubmed, although it is likely that most searches will result in large numbers of hits and reviewing the quality of large number of papers will be very time consuming. Alternatively, there are several of sources of evidence based medicine reviews. The Cochrane Library is a collection of databases that contain evidence-based reviews and is available through the National Electronic Library for Health and University libraries. Clinical Evidence from the BMJ Publishing Group provides a summary of the evidence available for managing a wide variety of conditions and includes an assessment of the quality of the evidence.
Guidelines
There has been a recent proliferation in the number of guidelines produced in developed countries to assist practitioners in a wide variety of clinical roles. They have been defined as ‘recommendations on the appropriate treatment and care of people with specific diseases and conditions’. However, it should be noted that foundations on which guidelines are based range from guidance based on good quality evidence to those based upon expert opinion. The quality of guidelines can also vary and prescribers must decide whether a guideline is suitable for use in their practice. In addition, there are few if any guidelines that can provide guidance that is appropriate for 100% of patients and prescribers should not follow guidelines blindly but consider which situations the guideline should be used and those when it should not. If a prescriber decides to deliberately deviate from a guideline they should document their reasons for deviation in the patient’s medical notes.
The National Institute for Health and Care Excellence (NICE) is an independent organization responsible for providing ‘national guidance on the promotion of good health and the prevention and treatment of ill health’. NICE provides guidance to support the management of a wide range of clinical conditions. The Scottish Intercollegiate Guidelines Network (SIGN) produce evidence-based clinical guidelines for use by people working in the health service and for patients.
Computerized decision support
Software is available that can assist healthcare professionals with diagnosis and prescribing. Relevant patient information such as age, sex, symptoms, laboratory tests are entered into the computer and this software compares these with information held on a database, to suggest a diagnosis or further investigations that might be required. The NHS previously funded a service to help healthcare professionals make evidence-based decisions for their patients. This service, called Clinical Knowledge Summaries (CKS), is not currently being maintained by the NHS, although it is available through the NHS Evidence website (www.evidence.nhs.uk). CKS also provides a clinical summary of recommendations for managing the patient’s condition and information to enable the writing of a prescription as well as providing access to patient information leaflets.
Formularies
Drug formularies are lists of medicines that prescribers use. These range from personal formularies from an individual prescriber to formularies used by one or more general practices or one or more hospital Trusts. It has been claimed that formularies can improve prescribing by improving prescriber familiarity with medicines as they only need knowledge of a limited range of medicines. Formularies that span different organizations have the potential to improve consistency of prescribing across the primary secondary care interface (see Ch. 23).
The process of producing a formulary can be very time consuming but it can be educational for those contributing to the process. It provides organizations with the opportunity to compare different medicines within a class on the grounds of effectiveness, safety, patient acceptability and cost and to consider which medicines they wish to see prescribed by prescribers in their organization. Deciding who to invite onto a formulary group to produce a new formulary is an important stage in the process. In small organizations such as a general practice, it is likely that all prescribers would be involved in the selection of drugs but care should be taken to include the views of those affected by the formulary such as the practice nurse, health visitors, district nurses and community pharmacists. In larger organizations it would not be feasible to include everybody in the formulary group but where possible, representatives from each section or department should be included to enable feedback to the rest of their section or department.
The methods used to inform prescribers regarding the formulary is another important step in the process especially in large organizations as prescribers could be unaware of its existence. The cost of printing and distributing paper copies of the formulary will depend upon the quantity involved and type of binding that is used ranging from a printed book to a ring binder with photocopied sheets. The formulary group should consider how often the formulary will be updated and how user friendly the format is to its prescribers, i.e. is it small enough to take of ward rounds or visit patients in their home. With computer generated prescribing the formulary medicines can often be highlighted or listed before non-formulary medicines.
In general, formulary groups should not expect 100% compliance with a formulary because there are always likely to be exceptional patients that do not respond to or have an ADR to certain drugs. The formulary group should therefore decide what level of compliance with the formulary they wish to see and also how they can monitor the actual compliance with the formulary. In some areas they will have no power to insist that formulary medicines are prescribed and they will have to persuade prescribers to consider formulary drugs first. If compliance with the formulary is particularly low then the formulary group should reflect on the suitability of the formulary (are the right drugs in the formulary?) and method of disseminating the formulary (are prescribers aware of the formulary and is it in a format they can use easily in their work?).
Competency framework
The National Prescribing Centre (NPC) was an NHS organization (now subsumed into NICE) that aimed ‘to promote and support high quality, cost effective prescribing and medicines management across the NHS, to help improve patient care and service delivery’. The NPC has produced a competency framework which brings together the knowledge, skills, motives and personal traits that are considered to be required by a prescriber working effectively. This framework should be used as a checklist by prescribers preparing to prescribe for the first time and also by prescribers reviewing their own practice as part of their continuing professional development.
Key Points
The prescribing of medicines is the most common medical intervention
Good prescribing has four elements: to maximize effectiveness, minimize risk and cost and to respect patient choice
The prescribing process has five component stages
Training requirements are laid out for non-medical prescribers
Independent prescribers diagnose and prescribe
Supplementary prescribers prescribe in response to the diagnosis of an independent prescriber
Evidence-based medicine allows healthcare professionals to compare the evidence for different treatment options and make the best decisions for the patient