| Date | November 2013 | Marks available | 2 | Reference code | 13N.3.SL.TZ0.1 |
| Level | Standard level | Paper | Paper 3 | Time zone | TZ0 |
| Command term | Suggest | Question number | 1 | Adapted from | N/A |
Question
Inadequate filtering of waste products from the blood is known as kidney failure. If this condition is found in a patient, or albumin is present in their urine, it shows that the patient has chronic kidney disease. Type II diabetes is the leading cause of chronic kidney disease in Australia. The bar graph shows the frequency of kidney failure in patients with type II diabetes in different Australian ethnic groups. It also shows the level of albumin in the urine of patients with both type II diabetes and kidney failure.
State the ethnic group with the lowest frequency of kidney failure.
State the frequency of both kidney failure and greater than normal albumin levels in patients of European ancestry with type II diabetes.
. . . . . . . . . . . . . . . . . . %
Compare the levels of albumin in urine of patients with kidney failure in the different ethnic groups.
The usual method of screening for chronic kidney disease is to test for kidney failure. Using the data in the bar chart, suggest why this method leads to more cases being missed in patients of indigenous Australian ancestry than in patients with European ancestry.
Markscheme
Asian
11.5(%) (allow answers in the range of 11(%) to 12(%))
(NOTE: question is worded awkwardly but if students give both 24.5% and 11.5% do not give credit)
all ethnic groups show range (very high, high and normal) of albumin levels;
greatest frequency of very high levels of albumin found in Pacific Islander patients/ European ancestry patients have lowest frequency of very high levels of albumin;
greatest frequency of high levels of albumin in Indigenous Australian/European ancestry patients / lowest frequency of high levels of albumin in Pacific Islander patients;
European ancestry patients have highest frequency of normal levels of albumin / Indigenous Australian/Pacific Islander patients have lowest frequency of normal levels of albumin;
European ancestry patients have highest/higher frequency of kidney failure but more than half/a large percentage have a normal level of albumin;
Indigenous Australian patients have lower frequency of kidney failure but higher levels of albumin;
it would be better to test for both kidney failure and albumin levels;
Examiners report
Candidates had no problem with the use of the bar chart to state which group had the lowest frequency of kidney failure, with most getting this mark.
Most also used the bar chart to find the correct value of 11.5% although some seemed to misunderstand the question, giving two answers. This ambiguity seemed to be caused by the use of the word ‘both’ in the question. This led some candidates to give both 24.5% (for percentage with kidney failure) as well as 11.5% (for greater than normal albumin levels). As long as the 11.5% was clearly in the answer, the mark was awarded.
The responses to this question were often awkward and it seemed that some did not understand the data in this stacked bar chart so they did not make valid comparisons between the levels of albumin in the ethnic groups. Few were able to get the full 3 marks.
Almost all candidates found this question difficult and very few correct replies were seen. Many related their responses to perceived social inequities, not the data provided.
