Significance tests A null hypothesis (H0) states that two treatments are equally effective (and is hence negatively phrased). A significance test uses the sample data to assess how likely the null hypothesis is to be correct. For example: there is …
Cohort studies – relative risk Study design The following table highlights the main features of the main types of study Randomized controlled trial Participants randomly allocated to intervention or control group (e.g. standard treatment or placebo) Practical or ethical problems …
Experimental event rate, EER = 10 / 100 = 0.10 Control event rate, CER = 50 / 300 = 0.166 Therefore the relative risk = EER / CER = 0.1 / 0.166 = 0.6 Relative risk Relative risk (RR) is …
Long QT syndrome Long QT syndrome (LQTS) is an inherited condition associated with delayed repolarization of the ventricles. It is important to recognise as it may lead to ventricular tachycardia and can therefore cause collapse/sudden death. The most common variants …
This is a classic presentation of spinal stenosis. Whilst peripheral arterial disease is an obvious differential the characteristic relieving factors of the pain and normal vascular examination point away from this diagnosis. Lower back pain Lower back pain (LBP) is …
A contingency table can be constructed from the above data, as shown below: PE diagnosed No PE Test positive 30 5 Test negative 10 55 The sensitivity is therefore 30 / (30 + 10) = 75% Screening test statistics It …
Next question Heparin There are two main types of heparin – unfractionated, ‘standard’ heparin or low molecular weight heparin (LMWH). Heparins generally act by activating antithrombin III. Unfractionated heparin forms a complex which inhibits thrombin, factors Xa, IXa, XIa and …
Cisplatin is associated with hypomagnesaemia Cytotoxic agents The table below summarises the mechanism of action and major adverse effects of commonly used cytotoxic agents Cytotoxic Mechanism of action Adverse effects Vincristine Inhibits formation of microtubules Peripheral neuropathy (reversible) Cisplatin Causes …
Vincristine – peripheral neuropathy Vincristine is associated with peripheral neuropathy. Urinary hesitancy may develop secondary to bladder atony. Cytotoxic agents The table below summarises the mechanism of action and major adverse effects of commonly used cytotoxic agents Cytotoxic Mechanism of …
Capecitabine is an orally administered prodrug which is enzymatically converted to 5-fluorouracil in the tumour. Cytotoxic agents The table below summarises the mechanism of action and major adverse effects of commonly used cytotoxic agents Cytotoxic Mechanism of action Adverse effects …