This assignment is based on the learning objectives and concepts in Topic 1. There are a total of 48 marks and this assignment will contribute 20% towards the total assessment for this subject. Your assignment should be typed, with adequate space left between questions. Assignments should be submitted via vUWS (see specific instructions relating to Assignment 1 on vUWS). Be as brief as possible in your answers, and use the number of marks for a question as a guide to how much to write. No answers need to be longer than a few short sentences or short paragraphs. Late assignments will not be accepted without prior approval. Remember to save your assignment as: Family name_First name_StudentID_Ass1 Question 1: In 2006, a group of 4,233 men and women aged 20 years were recruited from the general population and assessed for Herpes Simplex Virus - Type 2 (HSV-2). 288 participants were found to have HSV-2 when tested at baseline. Participants who did not test positive for HSV-2 in 2006 were followed-up and assessed again after 4 years of follow-up (only those who previously had tested negative for HSV-2 were tested again at follow-up). A further 99 cases of HSV-2 were identified during this 4 year period, either diagnosed during the interim or diagnosed during the study assessment. (It is assumed that once participants contract HSV-2 they remain HSV-2 positive.) (a) What was the prevalence of HSV-2 among study participants in 2006? (b) What was the prevalence of HSV-2 among study participants after 4 years of follow-up? Assume no loss to follow-up. [2 marks] (c) What was the cumulative incidence of HSV-2 among study participants over the study period? [4 marks] (d) Calculate the total number of person-years at risk during the 4 year period. (Assume that HSV-2 was acquired randomly during the 4 year period. That is, those who acquired HSV-2 were at risk for half the time of those who did not acquire HSV-2). [4 marks] (e) What was the incident rate of HSV-2 among participants for the 4 years. [4 marks] (f) Assuming that the incidence rate of HSV-2 remains constant, what should happen to the prevalence of HSV-2 in this cohort over time? Question 2: Question 2 relates to the following table of male suicide in the Sydney metropolitan area, stratified by quintile of socio-economic status (SES). (Only the lowest and highest SES groups are shown). Note: 5 years of death data are presented. Population data comes from a single census year (2011). It is conventional to present mortality rates as annual average rates. Lowest SES quintile, SuicidesLowest SES quintile, PopulationHighest SES quintile, SuicidesHighest SES quintile, PopulationTotal suicide (All quintiles)Total population (All quintiles) 2009-201320112009-201320112009-20132011 Males 15-24 195 123,961 116 140,942 779 667,548 25-34 242 134,303 158 134,595 1,044 693,988 35-44 204 133,242 123 135,819 865 688,839 45-54 147 110,680 92 124,576 594 577,128 55-64 89 83,943 55 75,308 364 381,248 65-74 76 73,509 42 56,097 283 304,226 75+ 56 39,197 43 36,293 224 172,856 1,009698,835629703,6304,1533,485,833 (a) Calculate the crude suicide incidence rate (per 100,000) for the lowest SES quintile and the highest SES quintile for those aged ≥15 years. [4 marks] (b) Calculate the direct age-standardised suicide incidence rate (per 100,000) for the lowest SES quintile using the highest SES quintile as the standard. [4 marks] (c) Is age an important factor in understanding differences in suicide between low and high SES groups? Using the age-specific data provided, make a specific comment about the difference between the crude suicide rate and the direct age-standardised suicide rate. [4 marks. (d) Calculate the crude mortality ratio (%) for lowest SES quintile relative to the highest SES quintile [2 marks] (e) What is the directly age-standardised mortality ratio (%) for the lowest SES quintile relative to the highest SES quintile? [2 marks] (f) Using the suicide incidence rates in the highest SES quintile as the standard, what is the indirect age-standardized mortality ratio (%) of the lowest SES quintile relative to the highest SES quintile? [4 marks] Question 3: Table 1: Life-table for Australian women (2002). Age interval Cases Pop mx qx px (1-qx) lx dx Lx Tx ex 0-4 778 653130 0.0012 0.0059 0.9941 100000 594 498515 8158584 81.6 5-9 82 663841 0.0001 0.0006 0.9994 99406 61 496877 7660069 77.1 10-14 119 667075 0.0002 0.0009 0.9991 99345 89 496503 7163191 72.1 15-19 215 647172 0.0003 0.0017 0.9983 99256 165 495869 6666689 67.2 20-24 271 695293 0.0004 0.0019 0.9981 99091 193 494975 6170819 62.3 25-29 210 723166 0.0003 0.0015 0.9985 98899 143 494134 5675844 57.4 30-34 316 745428 0.0004 0.0021 0.9979 98755 209 493253 5181710 52.5 35-39 562 759326 0.0007 0.0037 0.9963 98546 364 491820 4688457 47.6 40-44 767 704151 0.0011 0.0054 0.9946 98182 533 489577 4196637 42.7 45-49 1096 663482 0.0017 0.0082 0.9918 97649 803 486235 3707061 38.0 50-54 1088 512656 0.0021 0.0106 0.9894 96845 1022 481672 3220825 33.3 55-59 1839 419013 0.0044 0.0217 0.9783 95823 2080 473916 2739153 28.6 60-64 2617 364342 0.0072 0.0353 0.9647 93743 3307 460448 2265237 24.2 65-69 4215 365846 0.0115 0.0560 0.9440 90436 5064 439520 1804789 20.0 70-74 6545 338062 0.0194 0.0923 0.9077 85372 7883 407154 1365269 16.0 75-79 8703 254801 0.0342 0.1573 0.8427 77490 12193 356966 958115 12.4 80-84 11412 185023 0.0617 0.2672 0.7328 65297 17447 282867 601149 9.2 85-89 10967 99814 0.1099 0.4310 0.5690 47850 20623 187693 318281 6.7 90+ 10221 49022 0.2085 1.0000 0.0000 27227 27227 130588 130588 4.8 (a) This is a plot of the mx on a log10 scale. Describe the main characteristics of this plot. (Note: Plots are conventionally square unless there is a good reason to present data otherwise. That is, x and y axes should be the same length.) (b) What is the life expectancy at birth for Australian women based on the completed life-table? [2 marks] (c) To what age could a person aged 60 years expect to live? [2 marks] (d) Describe 2 shortcomings of the life-expectancy measure. (Limit of half a page. Please note: No more than half a page of text will be marked) [4 marks]