12 credit credit hours Student Age Number newly depressed by PHQ 9

12 credit credit hours student age number newly

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>12 credit hours 10-12 credit hours Student Age Number newly depressed by PHQ-9 Total students Number newly depressed by PHQ-9 Total students 17-19 30 208 112 1,000 19-20 41 278 150 1,002 21-22 296 1,306 131 468 >22 247 708 15 30 Total 614 2,500 408 2,500
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Question 21 Cumulative incidence for >12 credit hrs: 614/2500 = 24.6/100 Cumulative incidence for 10-12 credit hrs: 408/2500 = 16.3/100 Risk difference (RD) = 24.6/100 - 16.3/100 = 8.3/100 (per UW quarter) >12 credit hours 10-12 credit hours Student Age Number newly depressed by PHQ-9 Total students Number newly depressed by PHQ-9 Total students 17-19 30 208 112 1,000 19-20 41 278 150 1,002 21-22 296 1,306 131 468 >22 247 708 15 30 Total 614 2,500 408 2,500
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Question 22 Calculate the age-adjusted cumulative incidence of depression in the >12 credit group, using the 10-12 credit group as your standard population. >12 credit hours 10-12 credit hours Student Age Number newly depressed by PHQ-9 Total students Number newly depressed by PHQ-9 Total students 17-19 30 208 112 1,000 19-20 41 278 150 1,002 21-22 296 1,306 131 468 >22 247 708 15 30 Total 614 2,500 408 2,500
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Question 22 Direct Adjustment! Step 1: determine (or calculate) the standard (reference) population. Here, we use the population with 10-12 credit hrs. >12 credit hours 10-12 credit hours Student Age Number newly depressed by PHQ-9 Total students Number newly depressed by PHQ-9 Total students 17-19 30 208 112 1,000 19-20 41 278 150 1,002 21-22 296 1,306 131 468 >22 247 708 15 30 Total 614 2,500 408 2,500
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Question 22 Step 2: Calculate confounder stratum-specific measures of disease frequency. Age is the confounder here. Calculate age- specific cumulative incidences for those with >12 credit hours. >12 credit hours 10-12 credit hours Student Age Number newly depressed by PHQ-9 Total students Age-specific Cumulative Incidence Number newly depressed by PHQ-9 Total students 17-19 30 208 30/208=0.144 112 1,000 19-20 41 278 41/278=0.147 150 1,002 21-22 296 1,306 296/1,306=0.227 131 468 >22 247 708 247/708=0.349 15 30 Total 614 2,500 408 2,500
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Question 22 Step 3: Calculate the expected number of cases using the standard population >12 credit hours 10-12 credit hours Student Age Number newly depressed by PHQ-9 Total students Age-specific Cumulative Incidence Expected cases Number newly depressed by PHQ-9 Total students 17-19 30 208 30/208=0.144 0.144*1000=144.23 112 1,000 19-20 41 278 41/278=0.147 0.147*1002=147.78 150 1,002 21-22 296 1,306 296/1306=0.227 0.227*468=106.07 131 468 >22 247 708 247/708=0.349 0.349*30=10.47 15 30 Total 614 2,500 408 2,500
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Question 22 Step 4: Sum the expected cases from each level of the confounder. >12 credit hours 10-12 credit hours Student Age Number newly depressed by PHQ-9 Total students Age-specific Cumulative Incidence Expected cases Number newly depressed by PHQ-9 Total students 17-19 30 208 30/208=0.144 0.144*1000=144.23 112 1,000 19-20 41 278 41/278=0.147 0.147*1002=147.78 150 1,002 21-22 296 1,306 296/1306=0.227 0.227*468=106.07 131 468 >22 247 708 247/708=0.349 0.349*30=10.47 15 30 Total 614 2,500 408.55 408 2,500
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Question 22 Step 5: Calculate age-adjusted cumulative incidence for the >12 credit hours group. >12 credit hours 10-12 credit hours Student Age Number newly depressed by PHQ-9 Total students Age-specific Cumulative Incidence Expected cases Number newly depressed by PHQ-9 Total students 17-19 30 208 30/208=0.144 0.144*1000=144.23 112 1,000 19-20 41 278 41/278=0.147 0.147*1002=147.78 150 1,002 21-22 296 1,306 296/1306=0.227 0.227*468=106.07 131 468 >22 247 708 247/708=0.349 0.349*30=10.47 15 30 Total 614 2,500 408.55 408 2,500 408.55/2500 = 16.3/100
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Question 23 What is the age-adjusted risk difference of depression comparing students in the >12 credit hours group to students in the 10-12 credit hours group?
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