Flashcards in PA20298 evidence based medicine Deck (120):
Are chance, bias and confounding CAUSAL of a certain event?
No they are not causal.
If non of these were present, then ONE VARIABLE IS CAUSAL OF THE OTHER VARIABLE. If one or more of these factors are present, we cannot be sure if one variable causes what happens to the other variable.
What types of trials happen in drug development?
Pre clinical trials during research
Phase I,II and III clinical trials
Post marketing evaluation trials
What are randomised controlled trials (RCT) distinguishing feature?
Study subjects are RANDOMLY allocated to receive one or other of the alternative treatments under study. I.e group 1 may receive a new treatment whilst group 2 receive old treatment or a placebo.
The 2 groups of subjects are followed up in exactly the same way, the only difference between them is the care they receive.
What is the most important advantage of proper randomisation being done in randomised controlled trials?
It minimises allocation bias.
What are inclusion and exclusion criteria?
A way of establishing precision in your cohort/ case control study.
They define the population that will be included in your study.
Criteria that must be met for people to be included/ excluded in your study.
It is important to ensure that no group of people is included or excluded for a non scientific reason.
They effect the extent to which the results of a study can be generalised to the whole population.
What is inclusion criteria?
The criteria for including a patient in the study. What characteristics must a patient have to be included in the study?
What happens if inclusion criteria is too narrow?
if the criteria are too narrow, subject recruitment may be difficult
What happens if the inclusion criteria are too broad?
if the criteria are too broad this may reduce the level of control in the study design, as it increases the chance that the groups may differ/be effected by some other variable.
If the groups differ in any way other than the treatment, a confound has been Introduced, that could lead to incorrect conclusions..
What do Randomised control trials need to consider?
Carefully selected and specified indications (valid reasons to use a certain treatment)
Consider use of a homogeneous population (consider inclusion and exclusion criteria)
Short term therapy- cant have people coming back for checkups 20 years later, want a quick answer.
Can use randomised controlled trials to detect side effects of a treatment.
What is pharmacoepidemiology?
The principles of chronic disease epidemiology applied to the area of clinical pharmacology.
What happens with non-experimental/ observational studies?
an observational study draws conclusions on the possible effect of a treatment on subjects, where the assignment of subjects into treated and non treated control groups is outside often control of the investigator. These are NOT EXPERIMENTS!
There is no control over exposures assigned so the only source of discretion is the selection of the subjects.
Confounding will occur, as less control over the population picked for the study.
No risk to patients
What are cohort studies?
This study identifies a group of people and follows them over a period of time to see how their exposures effect their outcomes. Cohort studies are normally used to look at the effects of suspected risk factors that cannot be controlled experimentally, for example the effect of smoking on lung cancer.
It is a type of observational study.
A cohort is a group of people who share a COMMON CHARACTERISTIC. The comparison group may be e rest of the population or a group who have not been exposed to the treatment, I.e the control group.
Advantages and disadvantages of cohort studies?
Efficient for rare exposures
Multiple effects can be studied
Less prone to bias
Can calculate incidence rate, relative risks, and absolute risks
Can have difficulties with loss of follow up
May have problems with BIAS
What are case control studies?
An epidemiology study
Often used to identify risk factors for a medical condition
Compares a group of patients who have the condition with a group of patients who don't, and looks back in time to see how the characteristics of the two groups differ.
Case control studies are often used to identify factors that may contribute to a medical condition by comparing subjects who have the condition/ disease with patients that don't but are otherwise similar (the controls)
In case control studies, what do the case subjects have? What do the control subjects have?
Cases- have disease of interest
Controls- are free from the disease of interest
You're comparing the differences before treatment, in risk factors, protective factors, etiologic agent (causal agent/microorganism)
Advantages of case control studies?
Evaluation of rare diseases.
Diseases with long latent (inactive) periods
Relatively quick to conduct
Allows study of multiple exposures (to a drug/ treatment)
No risks to subjects
Useful in early stages when identifying potential risk factors of disease.
Disadvantages of case control studies?
Inefficient for rare exposures
Difficult to choose an appropriate control group
Prone to BIAS
What is bias in studies?
The introduction of systematic error in the study. This may be at the point of study design. It cannot be eliminated at the point of analysis.
Bias may be in terms of;
Selection of study subjects
Exposure (treatment) classification for each patient
Bias can result in over or underestimated risks
Why are randomised controlled trials randomised?
To eliminate confounding (outcome effected due to some other variable)
Examples of some confounding factors?
Newer drugs given to iller people, therefore they may appear to have more side effects when it's really just effects of having the illness
Smokers are more likely to have adverse health outcomes,so the medications they're taking are more likely to have advers side effects
Older people may be more likely to have more side effects
Confounding is a result of certain characteristics in the study population.
It can be dealt with through;
Randomisation of exposure
Confounding is the distortion of a risk estimate due to the mixture of the people in the study population.
A confounder is a risk factor for the disease and is correlated with the exposure independent of disease.
What must pharmacists consider when conducting a clinical check?
How treatment will be administered and monitored
What does clinical pharmacy generally describe?
Knowledge, skills and attitudes required by a pharmacist to contribute to patient care.
Pharmacists provide care that optimises medication therapy and promotes health, wellness and disease prevention.
Blends a caring orientation with specialised therapeutic knowledge, experience and judgment to ensure optimal patient outcomes.
What has pharmaceutical care been defined as?
The responsible provision of drug therapy for the purpose of achieving definite outcomes that improve a patients quality of life
What do clinical pharmacist do before the prescription?
Prescribing advice to doctors
Develop prescribing guidelines and tools
Medicines reconcilliation/ history taking
What do clinical pharmacists do during the prescription?
Clinical check of the prescription
Counselling the patient
What do clinical pharmacists do after the prescription?
Monitor the effectiveness (drug and disease)
Monitor adverse effects (side effects)
Ongoing patient counselling
Medicines usage review
Why do we need clinical pharmacists?
To improve patient care and increase effectiveness
Reduce adverse drug events such as prescribing errors, interactions, side effects
What do the patient factors consist of in a clinical check?
Age and sex
Allergies and intolerances
What are the medication factors of a clinical check?
Dose, frequency, check
Monitoring of effectiveness
What are the essential, advanced and enhanced terms of the NHS contract of a pharmacist?
Essential (must do);
Advanced: (can do)
Enhanced: prescribing, near patient testing
What is medicines reconciliation ?
The aim of medicines reconciliation on hospital admission is to ensure that medicines prescribed on admission correspond to those that the patient was taking before admission. Details to be recorded include the name of the medicine(s), dosage, frequency, and route of administration. Establishing these details may involve discussion with the patient and/or carers and the use of records from primary care. This does not include medicines review.
Pharmacists check and amend prescriptions written by doctors.
What does clinical pharmacy underpin in the community pharmacy?
Medicines use review
In hospital pharmacy what does clinical pharmacy underpin?
Stock checks/ supple checks; inpatient supplies and to take away medicines for outpatients.
Ward visits- patient counselling, medicines reconcilliation
Total parenteral nutrition,IV chemotherapy
What is a medication safety incident?
Any unintended or unexpected incident resulting from an irregularity in the process of medications use, which could have or did lead to patient harm.
What is an adverse drug event (ADE)?
Injury resulting from medical intervention related to a drug.
Under this definition, it includes harm caused by the drug (adverse drug reactions and overdoses) and harm from the use of the drug (such as discontinuation from therapy)
What is a adverse drug reaction?
A response to a drug which is noxious and unintended and which occurs at doses normally used in man for prophylaxis ( prevention / protective treatment of disease), diagnosis, and therapy of the disease, or for the modification of physiological function.
What is a medication error?
Incidents in which there has been an error in the process of prescribing, dispensing, preparing, administering, monitoring or providing medicines advice, regardless of whether any harm occurred.
Types of adverse drug reactions? Types A, B and C
Type A: augmentation ( increased action of) of pharmacological action: it is common and predictable, eg. Decrease in heart rate with beta blockers. They act to decrease blood pressure so this decrease in HR is predictable.
Type B: bizarre reaction. Unpredictable, eg an allergic reaction to penicillin.
Type C; dose related and time related, related to cumulative dose.
Adverse drug reactions types D E and F?
D; time dependent reactions. Occur some time after the drugs been used.
E; withdrawal reactions. Eg. Opioid withdrawals
F; unexpected failure of therapy; often caused by drug interactions, eg failure of oral comtraceptions in the presence of enzyme inducers
How are adverse drug reactions reported?
Reported to the UK medicines healthcare products authority using Yellow Cards
Can be reported by healthcare professionals and patients
What should ADRs be reported for?
All black triangle drugs
Suspected ADRs in children
Serious ADRs for established medicines and vaccines
Any delayed drug effects
What is a prescribing error?
Prescribing decision or prescription writing process that results in unintentional, significant reduction in the probability of treatment being timely and effective or InCREASe the risk of harm when compared with generally accepted practice.
What kinds of clinical checking errors exist for dispensing?
Inappropriate drug prescribed for patients condition
Inappropriate dose/ directions
Inappropriate formulation of drug
Drug interactions present
Drug- disease interaction present
What types of preparation errors exist for dispensing?
Selecting the wrong drug
Selecting the wrong strength
Selecting the wrong diluent
Drug not completely dissolved
Common administrations errors?
Administer medication at wrong time
Failing to administer a medicine
Administration using the wrong technique / via the wrong route
Some common causes of medication errors?
Lack of knowledge about patients/ medicines
Workload too big
What are clinical guidelines in place for?
Improve reproducibility of practice
Produced by expert bodies in specific clinical areas such as the British hypertension society
Produced by clinical advisory bodies to produce national guidelines eg. NICE
What are integrated care pathways ?
Single document which brings together multidisciplinary responsibilities I.e, role of doctor, role of nurse, role of pharmacist
They are PATIENT SPECIFIC
THEY'RE WRITTEN FOR A SINGLE CLINICAL CONDITION
They're guides only and are not intended to replace individual clinical judgement.
What do integrated care pathways include?
Specific treatment objectives
Timed treatment objectives
Guidance on review of patient
Defined monitoring criteria
The roles and responsibilities of each professional Are defined within these. (doctors nurses pharmacist)
Why do we use integrated care pathways?
Define goals of treatment
Define roles of the healthcare team
Deliver patient focused care
How do integrated care pathways effect a pharmacist?
Involvement in development and application of the ICP
Educational tool for the pharmacist
Provide a differential diagnosis
Provide a framework for monitoring the patient, the disease and the effectiveness of treatment.
What do care plans include?
Planned action of care for an individual
Expected progress of individual
Intended outcome of medication
Expected timescale of use of that medication
Revise patient care
Monitor intended outcome
What are the columns of a care plan subtitled?
GOAL OR DESIRED OUTCOME
COMMENTS ON TREATMENT SELECTED OR ANY FURTHER INTERVENTION REQUIRED
MONITORING NEEDS (including biochemistry, patient observations, or disease or medication)
Care plans are all about providing cost effectiveness, efficacious, safe, evidence based care
Care plans are only ever as good as the person using them
Why do we monitor?
To monitor the severity/ progression of a disease state
To monitor the intended/ beneficial effect of a drug or other intervention
To monitor the adverse effects of the drug (side effects, interactions)
To monitor blood levels of a drug (toxicity, efficacy)
We monitor disease and the intervention (the things were doing to help the patient)
As pharmacists we are primarily interested in:
How the drug effects the patient (therapeutic and adverse effects)
How the patients condition may effect their handling of the drugs
When do we monitor?
When the drug being used is a cause for a concern eg warfarin
The disease state , will the disease effect the drug eg healthy / unhealthy liver
Depending on whether it's an acute or chronic disease- acute diseases have intensive monitoring.
Patient factors may decide whether monitoring should be done; premature babies, neonates, elderly, obese, malnourished
What are clinical laboratory services?
A support service to healthcare at a local level
Usually based within a hospital trust
These services are purchased by others within the hospital
What types of parameters can we monitor?
Serum drug concentrations
Signs and symptoms
What types of physiological parameters are there that we can monitor?
Blood pressure due to anti hypertensives
Heart rate due to beta blockers / digoxin
Heart rhythm due to anti-arrhythmics
Respiratory rate due to strong opioids
Temperature due to antibiotics
What is the value of the optimal blood pressure? Systolic and diastolic?
<120 mmHg systolic
<80 mmHg diastolic
What is the value of normal blood pressure? Systolic ? Diastolic ?
<130 mmHg systolic
<85 mmHg diastolic
High-normal blood pressure?
130-139 mmHg systolic
85-89 mmHg diastolic
Mild hypertension (grade 1) systolic blood pressure / diastolic blood pressure?
140- 159 mmHg systolic
90 - 99 mmHg diastolic
Medium hypertension blood pressure (grade 2) ?
160- 179 mmHg systolic
100-109 mmHg diastolic
What are the values of blood pressure for severe hypertension (grade 3)?
Over 180 mmHg systolic
Over 110 mmHg diastolic
What is stage 1 hypertension?
Clinic blood pressure is 140/190 mmHg or higher and subsequent ambulatory blood pressure monitoring (ABPM) or home blood pressure monitoring (HBPM) average blood pressure is 135/85 mmHg or higher
Why is stage 2 hypertension?
Clinic blood pressure is 160/100 mmHg or higher and subsequent ABPM daytime average or HBPM average blood pressure is 150/95 mmHg or higher.
What biological parameters do we monitor?
Creatine and urea: Renal function/ fluid status
Liver function tests: indicate type / timescale of damage
Cardiac enzymes: a good diagnostic tool for myocardial infarction, troponin in most commonly used
C-reactive protein (CRP) : an indicator of course of infection/ inflammation.
Tell me about CRP, what is it, what does it measure?
C- reactive protein
Indicator of course of infection/ inflammation
It is not an absolute measure, it's useful as a trend only.
It's a protein found in the blood, and it's levels rise in inflammation.
Liver function tests, what are we monitoring for? What do they indicate?
ALT or AST (transaminases) tend to indicate acute damage poss normal in chronic phase of disease.
Cholestasis (bile cannot flow from liver to duodenum) may involve ALP, Bilirubin and GGT.
ALP is High in infiltrative liver disease.
What is creatinine?
It is a BY-PRODUCT of muscle metabolism.
It is excreted by the kidneys.
The amount of creatinine in the blood is a measure of HOW WELL the kidneys are functioning.
What does FBC stand for?
Full blood count
It is a blood test
What does an FBC screen for?
White blood cell count
Red blood cell count
What is a folate test/ when is it requested?
To help diagnose the cause of macrocytic anaemia
Requested as follow up tests when large red blood cells cells and a decreased heamopoeitic concentration are found during an FBC test.
Folate and vitamin B12 are used to help evaluate the nutritional status of a patient with signs of malnutrition.
What is an INR test?
Stands for international normalised ratio
Measures how THIN the blood is
It measures HOW LONG IT TAKES FOR THE BLOOD TO CLOT
Used to monitor WARFARIN therapy!!!!!
A ratio of how long it takes anticoagulated blood to clot compared to normal blood.
What is APTT?
Activated partial thromboplastin time
Detects abnormalities in blood clotting
Used to monitor therapeutic effect with heparin
Why are FBC's done?
After a patient has received chemotherapy to track neutrophils
To track the course of infection
To identify and determine the side effects to drugs
To determine the type/ severity/ progress of anaemia
What is an anticoagulant/ anticoagulated blood?
Anticoagulant: a substance that prevents coagulation (CLOTTING) of blood
Anticoagulant medicines can be used in thrombotic disorders (formation of blood clots disorder)
What is the INR of normal blood? What do INRs higher/ lower than the desired target range indicate?
1.0- 1.5 is normal.
People of warfarin treatment (an anticoagulant, blood thinner) will have different target INR ranges to aim for with warfarin treatment.
Eg a target range of 2.0 to3.0 with deep vein thrombosis.
An INR lower than the desired range means the blood is 'not thin enough' or clots too easily. An INR higher than the desired range means blood is too thin.
Does anticoagulated blood have a higher or lower INR?
A Higher INR means the blood is anticoagulated therefore thinner.
Typically, a person who is not taking a blood thinning medicine has an INR of around 1.
People who are undergoing blood thinner therapy will have a higher INR.
If the INR is out of range it can lead to uncrontrollable bleeding. A value too low may increase your risk of a stroke.
What characteristics of a drug means we need to monitor drug levels?
Where there is a large degree of inter-patient variability (if we can't predict dose/effect very well).
If the drug has a narrow therapeutic index: toxic levels are close to therapeutic levels.
If odd pharmacokinetics means dose/response isn't very predictable. (eg zero order)
Why should phenytoin be monitored?
First order kinetics at low doses
Zero order kinetics at higher doses
Narrow therapeutic window
Small increases in dose of phenytoin can result in large increases in plasma levels.
Why monitor gentamicin?
Excreted by kidneys and toxic to kidneys
Monitor to avoid toxicity; pre dose levels must be less than 1mg/L
Why monitor vancomycin?
To confirm therapeutic levels and clearance
Why monitor tericoplanin?
Concerned about effectiveness
In microbiology testing, what can we take cultures from samples of?
What is evidence based medicine all about?
Efficacy versus effectiveness,
Use of current based evidence in making decisions about care of individual patients.
Integrates individual clinical expertise with the best available external clinical evidence from systemic research.
What is critical appraisal?
A way to assess the methods and results of published research.
Balanced assessment of the strengths of research against its weaknesses
All research and health professionals should undertake critical appraisal.
You're basically making your own assessment of articles/research papers.
Why would you critically appraise?
Not all research is reliable
Data doesn't always support researchers conclusions
Not all research may be relevant
Provides framework for interpreting research.
What are CASP forms?
Critical appraisal skills programme form
Aims to help individuals to develop the skills to find and make sense of research evidence , helping them to put knowledge into practice.
What is BIAS?
It is a systemic error in data
Bias consistently pulls the risk estimate away from its true value
What is non-differentiential and differential misclasification?
Non differential: misclasification to the same degree for All groups, all groups have the same error rate.
Differential: misclasification different between groups (error rate probability differs between groups).
What is misclasification bias in epidemiological studies?
Also known as information bias, or observation bias,
It essentially refers to bias arising from a measurement error.
What do generisable results mean?
Are the patients in the study like the ones you would expect to receive the treatment?
They may be healthier, younger etc... You want your results to be generalisable.
What are the 3 E's in pharmacoeconomics?
Equity: is there equality of access to healthcare for those with equal need? Is equal treatment being received?
Efficiency? Are we using our available resources to the max?
What are the benefits of economic evaluation?
Cost-minimisation analysis -simplest form, costs/inputs alone are compared.
Cost-effectiveness analysis- compares costs and benefits of interventions to determine their value for money. Most cost effective; greatest effectiveness at the lowest cost.
What is the incremental cost- effectiveness ratio (ICER) for comparing 2 alternatives determined by?
Difference in treatment costs divided by difference in effectiveness
What is cost-utility analysis? What's QALY?
Improvements in health care status are measured in terms of utility
Most common measure of utility is e QALY
QALY= quality adjusted life year
This is a measure of disease burden, including both the quality and quantity of life lived.
It is used to asses the value for money of a medical intervention
The QALY is based on the number of years of life that would be added by the intervention,
What do values 1, 0 and between 1-0 indicate in QALYS?
1= a year in FULL HEALTH
0-1 = illness or disability to varying diseases.
QALYS can facilitate comparisons across health car programmes in terms of health gain per unit of expenditure.
Improvements in health status are measured in terms of utility
The most common measure of utility is the QALY
QALYS determine health gain per unit of expenditure
Disadvantage of QALYS?
They're racist, sexist, ageist, difficult to interpret...
What do the following abbreviations
U & E's
What is a systemic review?
A review of the important systems of the body.
Usually the review starts with the systems relevant to the presenting complaint and then the other major systems of the body.
The findings of the systems review will be documented in the medical notes. Only positive data (e.g. shortness of breath on exertion) or important negative data (e.g. non-smoker) tends to be recorded.
Sometimes the absence of symptoms is denoted by the symbol ∘ne.g. ∘dyspnoea,
What does GU in patients medical notes stand for?
• Incontience/urgency/hesitancy/poor flow
Will be recorded under here.
What does JVP in the physicAl examination part of patient medical notes stand for?
• Jugular venous pressure (JVP)
useful in the differentiation of different forms of heart and lung disease
What is chest percussion?
Percussion is an assessment technique which produces sounds by the examiner tapping on the patient's chest wall, Creating motion, audible sounds and palpable vibrations.
Percussion helps to determine whether the underlying tissues are filled with air, fluid, or solid material.
What is the Glasgow Coma Scale?
The Glasgow Coma Scale or GCS is a neurological recording of the conscious state of a patient. A patient is assessed against the criteria of the scale, and the resulting points give a patient score between 3 (indicating deep unconsciousness) and either 14 (original scale) or 15 (the more widely used modified or revised scale).
GCS was initially used to assess level of consciousness after head injury, and the scale is now used by first aid, EMS, and doctors as being applicable to all acute medical and trauma patients.
What does gait mean on patients medical notes?
Human gait is the way locomotion is achieved using human limbs.
What do the triangle symbols in the diagnosis section of the medical notes indicate?
In this section the doctor will record his/her diagnosis. The abbreviations Dx or Δ are used to indicate a definitive diagnosis. (doctor is sure of this diagnosis)
Sometimes there may be a number of potential diagnoses, each known as a differential diagnosis, indicated by the abbreviation DD or ΔΔ. The medical team will then conduct a number of different investigations to establish the definitive diagnosis.
In progress reports (follow ups) in patients medical notes, what is the SOAPS criteria?
S = Subjective 1) Subjective data i.e. the patient’s symptoms
O = Objective 2) Objective data i.e. physical signs and results of any
A = Assessment 3) Interpretation of data from physical examination and
P = Plans 4) Immediate plans. 5) Therapy
What is pharmacoepidemiology?
The study of the use of and the effects of drugs in large numbers of people.
What knowledge is required to judge whether a medicine is safe and effective for use in patients?
Clinical trials assessing the effectiveness of medicines
Pharmacoepidemiological studies assessing the risk of medicines use
Pharmacoeconomic studies determining the cost-effectiveness of medicines
What are the three stages of medicines reconciliation?
Medication history: create a list, collect the info
Check and verify the list against current prescription
What sources of information are used to get information on the medication/ drug history of the patient?
GP prescribing record
What are the limitations of the ways you can collect a patients medication history?
The patient may not actually be taking the medicines on the prescriptions/ what the doctor tells you their on, it's down to the patient to take them/ tell you the truth.
A repeat slip would not include all the information on any non regular medicines.