| odds ratio | <epidemiology> A comparison of the presence of a risk factor for disease in a sample of diseased subjects and non diseased controls. The number of people with disease who were exposed to a risk factor ( I.e. ) over those with disease who were not exposed ( Io ) divided by those without disease who were exposed ( Ne ) over those without who were not exposed ( No ). Thus OR=(I.e./Io)/(Ne/No)= I.e. No / Io Ne. This measure should be used for case control studies where we retrospectively look at risks in those with and without disease. Also known as exposure odds ratio. (05 Dec 1998) |
|---|---|
| exposure odds ratio | <epidemiology> See Odds ratio. (05 Dec 1998) |
| odds | The ratio of probability of occurrence to non-occurrence of an event. Origin: pl. Of odd, fr. M.E. Odde, fr. O.Norse oddi, odd number (05 Mar 2000) |
| absolute terminal innervation ratio | The number of motor endplates divided by the number of terminal axons related to them. (05 Mar 2000) |
| accommodative convergence-accommodation ratio | The amount of convergence (measured in prism diopters of convergence) divided by the amount of accommodation (measured in diopters) required to direct both eyes upon an object. (05 Mar 2000) |
| A/G ratio | <abbreviation> Albumin-globulin ratio. (05 Mar 2000) |
| albumin-globulin ratio | The ratio of albumin to globulin in the serum or in the urine in kidney disease; the normal ratio in the serum is approximately 1.55. (05 Mar 2000) |
| ALT:AST ratio | The ratio of serum alanine aminotransferase to serum aspartate aminotransferase; elevated serum levels of both enzymes characterise hepatic disease; when both levels are abnormally elevated and the ALT:AST ratio is greater than 1.0, severe hepatic necrosis or alcoholic hepatic disease is likely; when the ratio is less than 1.0, an acute non-alcoholic hepatic condition is favoured. (05 Mar 2000) |
| amylase-creatinine clearance ratio | A test for the diagnosis of acute pancreatitis; it is determined by measuring amylase and creatinine in serum and urine in apparently healthy individuals the renal clearance of amylase is less than 5% that of creatinine; in acute pancreatitis the ratio is said to be greater than 0.05 or 5%. (05 Mar 2000) |
| aspect ratio | <radiobiology> In toroidal geometry, the ratio of the major diameter (total width of the torus) to the minor diameter (width of a slice taken through one side of the ring). In inertial-confinement fusion, aspect ratio refers to the ratio of a fuel pellet's radius to its wall thickness. (09 Oct 1997) |
| at/gc ratio | <molecular biology> The ratio of adenine-thymine base pairs to guanine-cytosine base pairs on a DNA molecule. (09 Oct 1997) |
| basic reproductive rate, ratio | <epidemiology> See Reproductive Ratio. (05 Dec 1998) |
| body-weight ratio | Body weight (in grams) divided by stature (in centimeters). (05 Mar 2000) |
| branching ratio | <radiobiology> In a fusion reaction involving two nuclei, there are typically a variety of possible sets of products which can form. The branching ratio for a particular set of products is the probability that that set of products will be produced. (09 Oct 1997) |
| cardiothoracic ratio | The ratio of the horizontal diameter of the heart to the inner diameter of the rib cage at its widest point as determined on a chest roentgenogram. (05 Mar 2000) |