Mandus Hard MCQs Flashcards
If the prevalence of a disease decreases, which of the following occurs?
- a) Specificity decreases
- b) Sensitivity increases
- c) Negative predictive value does not change
- d) Positive predictive value decreases
d) Positive predictive value decreases
D - as the prevalence of a disease decreases, the positive predictive value also decreases because the number of false positives will increase.
What is the best feature of a test for a disease that has low prevalence within a community?
a) A test with low sensitivity
b) A test with high sensitivity
c) A test with low specificity
d) A test with high specificity
What is the best feature of a test for a disease that has low prevalence within a community?
a) A test with low sensitivity
b) A test with high sensitivity
c) A test with low specificity
d) A test with high specificity
D - a test with high specificity will be able to rule out people without the disease who will make up most of the people that are tested. You want to be able to rule out people who are truly negative.
You are a doctor running a trial and find that the older a person is, the more likely they are to fall in nursing homes. However, after controlling for age, gender and medication use, you find that your correlation between age and falls is not significant. Which of the following is correct?
a) Age is not independently correlated with falls
b) You found these results by chance
c) There is no correlation
d) Other risk factors do not play a part in falls
You are a doctor running a trial and find that the older a person is, the more likely they are to fall in nursing homes. However, after controlling for age, gender and medication use, you find that your correlation between age and falls is not significant. Which of the following is correct?
a) Age is not independently correlated with falls
b) You found these results by chance
c) There is no correlation
d) Other risk factors do not play a part in falls
A - controlling for other factors shows that there were confounders that were leading you to an incorrect conclusion about the correlation between age and falls.
You conduct a study measuring the risk ratio of developing a new syndrome called RoryMichaelitis in people who drink VB vs people who don’t drink VB.
You produce the graph below showing the risk ratio with a 95% confidence interval of developing RoryMichaelitis in those who don’t drink VB (top line) and those who do (bottom line). What do you conclude?
- a) There is an increased risk of developing RM in people who do drink VB but not in those who don’t
- b) There is an increased risk of developing RM in people who don’t drink VB but not in those who do
- c) There is an increased risk in both groups
- d) There is no increased risk in either group
d) There is no increased risk in either group
D - while the risk ratio for each group is >1 indicating an increased risk, the confidence interval boundaries for both groups includes the risk ratio of 1 meaning that the neutral value is included in your estimate of uncertainty. You therefore cannot conclude that there is an increased risk because you could have easily found a risk ratio of 1 - no correlation.
Remember a confidence interval tells us the range of values that your risk ratio could be with 95% confidence. If you conducted your study 100 more times, the risk ratio would fall between those values. It’s impractical to do a study 100 times so a calculation of uncertainty allows you to show the range of all possible risk ratios that could have been generated.
What four factors differentiate between acceptable and non-acceptable sport injuries?
Intent - deliberate vs non-deliberate
Severity - minor and non-life threatening vs severe and disabling
Activity - intentional vs unintentional
Mechanism - regular or normal vs unnatural could be prevented.
A patient has just been told they have type 1 diabetes. What are some ways in which a chronic health condition can impact a person?
- Self esteem
- Role within society
- Quality of life
- Social and personal relationships
- Employment and education opportunities
- Financial cost
What are 4 outcomes that can be taken against a doctor who is impaired?
- No action taken
- Conditions placed on scope of practice
- Referred to another health practitioner for condition
- Suspension of license to practice
- Criminal proceedings
What is the difference between a disability and an impairment?
A disability is a condition that limits the scope of practice; however provisions are in place to ensure that the practitioner can still practice to an acceptable standard and therefore does not pose a risk to themselves or the public.
An impairment refers to a condition that is not being managed and the practitioner does pose a risk to the public.
What is the ABCD of palliative care?
- A - Attitude
- B - Behaviour
- C - Compassion
- D - Dialogue
What are the Bradford Hill criteria?
Well lit roads are which type of intervention in Haddon’s Matrix?
a) Pre event host
b) Post event environment
c) Pre event environment
d) Event vehicle
e) Event host
c) Pre event environment
C - ensuring that the environment is safe and prevents accidents from happening.
Which of the following is most beneficial to reduce someone’s risk of cardiovascular disease?
a) Using aggressive pharmacological therapy
b) Losing weight
c) Stopping smoking
d) Tackling 2 or more lifestyle factors
e) Reducing salt intake
d) Tackling 2 or more lifestyle factors
D - addressing more than one risk factor is more beneficial than addressing one single factor alone. Reducing multiple risk factors has a multiplicative effect on reducing someone’s risk of CVD.
Down syndrome is a chromosomal disorder that has been correlated to some predisposing factors. Which of the following is correct?
a) Maternal age is correlated to DS and more babies with DS are born from older women
b) Maternal age is correlated to DS but more babies with DS are born from younger women
c) Maternal age and regional status are both linked to DS with older, remote women giving birth to the most babies with DS
d) Maternal age and indigenous status are linked to DS and older, aboriginal women give birth to the most babes with DS.
e) Maternal age, aboriginal status and indigenous status are all linked to DS.
b) Maternal age is correlated to DS but more babies with DS are born from younger women
B - while maternal age is the most well documented risk factor for conceiving a child with down syndrome, more babies with down syndrome are born to younger women because younger women have more babies in total.
CF carrier frequency in population is around 1/2500. What is the likelihood that a woman with CF and a man who doesn’t know his genetic history will conceive a boy with CF.
- a) 4%
- b) 0.4%
- c) 2%
- d) 0.2%
- e) 0.004%
- a) 4%
- b) 0.4%
- c) 2%
- d) 0.2%
- e) 0.004%
Three researchers conduct an ecological study comparing alcohol use in Australia and Germany. What they find is that alcohol use is higher in women in Australia overall but in Germany, alcohol use is higher in people aged 60 for both genders.
Which of the following conclusions is an example of the ecological fallacy? (multiple answers)
a) Tighter laws around alcohol contribute to its lower use in Australia.
b) Younger people in Germany are more influenced by advertising against alcohol.
c) Germans have more permissive attitudes to alcohol.
d) Alcohol is more readily available in Germany
B and C - these two conclusions are assuming about the causation of the factors on the outcome of alcohol use by inferring from the results.
Both A and D are making conclusions about the factors that contribute to alcohol use and are not making assumptions about the populations being studied.
The ecological fallacy is when you take aggregate group data and apply it to the individual. Aggregate group data fails to control for multiple factors that show trends or correlation at the individual level. In this example, it is taking the outcome of all people aged over 60 and saying that they all drink too much whereas it may be only a small percentage of people who do and have pushed the average consumption rate in Germany above the average consumption rate in Australia. It could be that more Australians >60 drink more than they should but have been overshadowed by some serious drinkers in Germany.
Week 19
A woman presents and believes she is pregnant as her period is 3 weeks late. She believes she is pregnant. She discloses that wants to keep the baby and get a check up to ensure she can carry the pregnancy to term. What test would you not carry out?
a) Cervical screening
b) Blood test for immune status
c) Glucose tolerance test
d) Urinalysis
e) B-hcg test
f) Take vitals
g) Measure weight
c) Glucose tolerance test
C - this is the most inappropriate test to perform. Gestational diabetes will develop later in the pregnancy and is usually tested with the glucose tolerance test during week 24 - 28 of pregnancy, sometimes earlier. The reason that women develop gestational diabetes is because the placenta produces hormones to increase glucose in the blood for maternal tissues to metabolise and create energy. However, some women are unable to produce enough insulin to maintain normal blood glucose levels and become hyperglycaemic.
Which of the following is a cause of central cyanosis?
a) Cold temperature
b) Polycythemia
c) Vagal stimulation
d) Left ventricular heart failure
e) Pulmonary embolism
b) Polycythemia
B - polycythemia will result in a total amount of oxygenated haemoglobin circulating because the total number of RBCs available to oxygenate has increased. Therefore the percentage of oxy-haemoglobin that leaves the heart is decreased.
Which of the following cells is least associated with the pathophysiology of asthma?
a) Dendritic cells
b) Mast cells
c) Monocytes
d) Eosinophils
e) Plasma cell
C - Monocytes are non-mature pre-macrophage cells that circulate in the blood before they move into tissues and mature. They may link RSV and asthma but this link is not clear.
Dendritic cells sample the allergen and display it to Th2 cells which are responsible for cytokine production. IL-4 + IL-13 recruit plasma cells to produce IgE which bind to mast cells which degranulate upon binding to the antigen. Eosinophils are recruited by IL-5 which release histamine and other mediators when exposed to the antigen.
Which of the following results in an increase in bronchiole diameter?
a) Decreased O2
b) Increased CO2
c) Increased O2
d) Decreased CO2
e) AandB
b) Increased CO2
B - the control of V/Q is different to that of the systemic circulation.
● Increased alveolar air PCO2 => dilate bronchioles and dilate systemic arterioles
● Decreased PCO2 => constrict bronchioles and constrict systemic arterioles
● Increased PO2 => dilate pulmonary arterioles and constrict systemic arterioles
● Decreased PO2 => constrict pulmonary arterioles and dilate systemic arterioles
Which of the following regarding normal pulmonary pressures is correct?
a) Transpulmonary pressure is always negative
b) Transpulmonary pressure is always positive
c) Intrapulmonary pressure is always positive
d) Intrapulmonary pressure is always negative
b) Transpulmonary pressure is always positive
Which of the following regarding normal pulmonary pressures is correct?
a) Transpulmonary pressure is always negative
b) Transpulmonary pressure is always positive
c) Intrapulmonary pressure is always positive
d) Intrapulmonary pressure is always negative
b) Transpulmonary pressure is always positive
The macula densa is responsible for:
a) Releasing renin
b) Sensing ultrafiltrate NaCl concentration
c) Contracting the smooth muscle around the afferent arteriole
d) Releasing noradrenaline
e) Sensing aldosterone levels
b) Sensing ultrafiltrate NaCl concentration
B - the macula densa senses salt concentration and to a lesser extent the rate of fluid flow (they are ciliated cells). They then secrete adenosine or ATP to the juxtaglomerular granular cells to secrete renin.
They also secrete prostaglandins to increase afferent arteriole vasoconstriction and efferent arteriole vasodilation.
Which of the following is the correct pair?
a) Intra-renal AKI - high FeNa (fractional
excreted sodium)
b) Pre-renal AKI - low BUN/Cr ratio
c) Intra-renal AKI - high urine osmolarity
d) Oliguric phase of AKI - hypokalemia
e) Diuretic phase - low urine volume
a) Intra-renal AKI - high FeNa (fractional excreted sodium)
A - is correct. During an intra-renal cause of AKI, the tubules are damaged (by drugs, toxins or ischaemia) meaning that the transporters and exchangers are absent or not working optimally. In the proximal tubule especially, a decrease in their functioning means that much of the ultrafiltrate cannot be reabsorbed. This results in more of the ultrafiltrate forming part of the urine and therefore more sodium being excreted.
B - In pre-renal AKI, urea cannot be filtered so stays high and is therefore incorrect.
C - Intra-renal AKI is a problem with reabsorption and the urine is unable to be concentrated.
D - during the oliguric phase of AKI, potassium is retained and not filtered.
E - diuretic phase of AKI is when high volumes of urine are produced and can lead to hypokalemia and hyponatremia.
Which of the following is diagnostic of hypertension?
a) 120/80
b) 129/35
c) 140/80
d) 140/90
e) None of the above
D - 140/90 over three consecutive visits.
Which of the following layers are affected first in an ischaemic heart episode?
a) Epicardium
b) Outer myocardium
c) Inner myocardium
d) None of the above
C - the inner myocardium is furthest from the arteries and will hence become ischaemic before the better perfused outer layers.
Which of the following is not a site of action of PTH?
a) Kidney tubule
b) Bone
c) GI tract
d) Thyroid
d) Thyroid
D - The thyroid does not respond to PTH and secretes its own hormone in calcium regulation - calcitonin.
Which of the following is the cause of primary type I osteoporosis?
a) Old age
b) Menopause
c) Drug induced
d) Lack of sunlight
B - the primary cause of osteoporosis is the absence of estrogen which represses the action of IL-6. IL-6 upregulates RANKL expression on osteoblasts which subsequently activates osteoclast maturation.
Which of the following injuries would cause Trendelenburg’s Sign?
a) Posterior column damage
b) Cerebellar damage
c) Damage at the fibular head
d) Damage at L4-S1
e) Damage at L3-L4
D - damage at L4-S1 would injure the superior gluteal nerve which weakens the abductor muscles (gluteus medius and minimus). Weakness of the abductors shows a contralateral hip drop.
What changes would a posterolateral L4 disc herniation cause?
a) Changes to the knee jerk reflex
b) Changes to the ankle jerk reflex
c) Changes to the tone on the external sphincter
d) Changes to the bladder reflex
e) None of the above
E - none of the above. L4 disc herniation would cause a L5 compression which does not participate in any reflexes.
What changes would a posterolateral L4 disc herniation cause?
a) Changes to the knee jerk reflex
b) Changes to the ankle jerk reflex
c) Changes to the tone on the external sphincter
d) Changes to the bladder reflex
e) None of the above
E - none of the above. L4 disc herniation would cause a L5 compression which does not participate in any reflexes.
What is the type of wave present on an EEG during light sleep?
a) Alpha
b) Beta
c) Gamma
d) Delta
e) Theta
What is the type of wave present on an EEG during light sleep?
a) Alpha
b) Beta = concentration
c) Gamma = higher cortical functions
d) Delta = deep sleep
e) Theta
Which of the following is not a phase of wound healing?
a) Haemostasis
b) Exudative
c) Inflammatory
d) Proliferation
e) Maturation
B - exudate is formed during haemostasis.
Decreased ability for a patient to feel touch and vibration on the left leg is a result of what lesion?
a) Damage to lateral corticospinal tracts on the right
b) Damage to the spinocerebellar tracts on the right
c) Damage to the DCLM on the right
d) Damage to the DCLM on the left
e) Damage to the lateral spinothalamic tracts
- D - the dorsal column medial lemniscus pathway is responsible for fine touch, crude touch, vibration and conscious proprioception (know your arm is next to your body).
- The corticospinal pathways are for transmitting motor signals to the spinal cord.
- The spinocerebellar is responsible for transmitting unconscious proprioception (quite important in the joint capsule).
- Spinothalamic is responsible for transmitting pain and temperature.
Which one of the following occurs as a result of the ischaemic cascade?
a) Increased GABA synthesis
b) Increase rates of alanine breakdown
c) Excess glutamate release
d) Increased activity of ATP synthase
e) Decreased substrate level phosphorylation
c) Excess glutamate release
C - the decrease of oxygen results in decreased ATP. This decrease in cellular energy raises the level of depolarisation within the cell and results in calcium influx and glutamate release. This leads to excitotoxicity within the brain.
Which of the following is not given to a patient presenting with altered mental status?
a) Glucose
b) Naloxone
c) Thiamine
d) Carbamezapine
e) Flumazenil
d) Carbamezapine
D - the ‘coma cocktail’ includes thiamine (Vit B1), glucose in the case of hypoglycaemia, naloxone an opioid antagonist, and flumazenil a gaba antagonist to block the effects of benzodiazepines.
Which of the following would cause internuclear ophthalmoplegia and be seen as horizontal nystagmus?
a) Damage to the optic nerve
b) Damage to the cochlear nerve
c) Damage to the medial longitudinal fasciculus
d) Damage to the occipital lobe
e) Damage to the pretectal area
C - the medial longitudinal fasciculus is responsible for coordinating sideway movements of the eyes when somebody turns their head. When you turn your head to the left, both eyes turn to the right. For this to occur the medial rectus and lateral rectus have to coordinate. The medial longitudinal fasciculus is the pathway for the signals to move between the abducens and oculomotor nuclei.
The semicircular canals in the inner ear send signals to the pons area which then coordinates the abducens nuclei on the ipsilateral side to activate. This abducens nucleus causes a contraction of the lateral rectus on the contralateral side and sends signal via the medial longitudinal fasciculus to the ipsilateral oculomotor nucleus to contract so that both eyes rotate to the same side. Think about it for a second.
When the MLF is damaged, you will have uncoordinated sideways movement of the eyes called horizontal nystagmus.
What is not a common pathogen of middle ear infections?
a) Pseudomonas aeruginosa
b) Moraxella catarrhalis
c) Streptococcus pneumoniae
d) Haemophilus influenzae
A and D - the three common pathogens are listed. Pseudomonas is more common in external ear infections
The Trendelenburg Sign is indicative of what pathology?
a) Superior Vena Cava syndrome
B) Splenomegaly
C) Weakness of hip extensor (gluteus Maximus)
D) Weakness of hip abductors (gluteus medius and minimus)
The Trendelenburg Sign is indicative of what pathology?
a) Superior Vena Cava syndrome = positive Pemberton’s sign
B) Splenomegaly = inferred from a positive Castell’s sign.
C) Weakness of hip extensor (gluteus Maximus)
D) Weakness of hip abductors (gluteus medius and minimus)
The answer is D. Trendelenberg’s sign is found in people with weak of paralysed abductor muscles of the hip. The test is used to assess hip stability. Note A positive sign is elicited when the pelvis tilts down on the side contralateral to the weakness during stance
A 77 year old male presents to your GP practice complaining of erectile dysfunction. Which of the following is a NOT likely cause of his ED?
A) Stress
B) Obesity
C) Hypergonadism
D) Hypertension
E) Atherosclerosis
C) Hypergonadism
A is incorrect because mental state plays a big part in sexual arousal leading to erection.
B is incorrect because obesity lowers the amount of testosterone that can be produced in an older system which is already low in the androgen, hence leading to ED.
D is incorrect because prolonged hypertension can damage blood vessel wall lining leading to issues with tumescence for erections.
E is incorrect as atherosclerosis hardens blood vessels making it harder to obtain an erection
C is the correct answer. Hypogonadism would contribute to erectile dysfunction
A 77 year old male presents to your GP practice complaining of erectile dysfunction. Which of the following is NOT part of the deadly quartet, increasing the risk of erectile dysfunction?
A) Diabetes
B) Hypogonadism
C) Obesity
D) Hypertension
E) Dyslipidaemia
B) Hypogonadism
The deadly quartet refers to 4 conditions that constitute a metabolic syndrome which place a patient at a high risk of erectile dysfunction.
These are: Diabetes, Obesity, Hypertension Dyslipidaemia.
Therefore, the answer is B. Hypogonadism is a contributing factor ED, however it is not a part of the deadly quartet.
A 77 year old male presents to your GP practice complaining of erectile dysfunction. Which of the following is NOT part of the deadly quartet, increasing the risk of erectile dysfunction?
A) Diabetes
B) Hypogonadism
C) Obesity
D) Hypertension
E) Dyslipidaemia
B) Hypogonadism
The deadly quartet refers to 4 conditions that constitute a metabolic syndrome which place a patient at a high risk of erectile dysfunction.
These are: Diabetes, Obesity, Hypertension Dyslipidaemia.
Therefore, the answer is B. Hypogonadism is a contributing factor ED, however it is not a part of the deadly quartet.
In patients with obstructive lung disease, spirometry would most likely reveal a _______ FEV1:FVC ratio and a ________FVC.
A) normal; elevated
B) normal; reduced
C) decreased; normal/elevated
D) decreased; normal/reduced
In patients with obstructive lung disease, spirometry would most likely reveal a decreased FEV1:FVC ratio and a normal/reduced FVC.
Patients with obstructive lung disease exhibit the characteristic ‘scooped out’ spirometry curve with significantly decreased FEV1 but relatively normal, if not slightly reduced, FVC. Although air can be drawn in the same volume, there is a smaller airway for air to be forced out of and so it can’t move out as quickly.
In patients with restrictive lung disease, spirometry would most likely reveal a _______ FEV1:FVC ratio and a ________FVC.
A) normal; elevated
B) normal; reduced
C) decreased; normal/elevated
D) decreased; normal/reduced
In patients with restrictive lung disease, spirometry would most likely reveal a normal FEV1:FVC ratio and a reduced FVC.
Patients with restrictive lung disease demonstrate a smaller curve on spirometry that is proportional to the normal/expected curve. They have a loss of elasticity of the lung parenchyma and hence are unable to take in nor expel air fast enough leading to a relatively normal FEV1:FVC ratio but reduced values of FEV1 and FVC.
A 23 year old man presents to the ED with an acute exacerbation of asthma. Which of the following clinical signs would NOT be indicative of a severe asthma attack?
A) Low pulse rate
B) Silent chest
C) Speaks in only words
D) Low O2 saturation
E) Physical exhaustion with paradoxical chest movement
A) Low pulse rate
The answer is A as we would expect a high pulse rate (>120bpm) in this presentation.