1. For the following questions, you will be using several methods to investigate the precision/ reliability of 50 individuals who completed replicate 24-hour recalls. Specifically, you will be investigating the reproducibility of total fat intake (g) and Vitamin A intake (RAE) (mcg).

	24 Hour Recall- Day 1	24 Hour Recall- Day 2	FFQ
ID	Total Fat (g)	Vitamin A (RAE) (mcg)	Total Fat (g)	Vitamin A (RAE) (mcg)	Total Fat (g)
21005	101.42	127	93.24	200	149.12
21006	43	245	39.7	248	13.7
21007	32.86	199	33.86	161	18.96
21008	107.95	455	74.51	816	229.14
21009	235.64	835	200.6	532	342.2
21010	60.87	423	51.13	394	70.1
21012	113.14	336	112.68	89	191.3
21013	103.38	38	21.79	22	209.6
21014	70.65	406	58.73	989	73.68
21015	45.75	650	89.17	913	11.5
21016	70.73	586	57.21	628	78.66
21017	70.08	99.5	74.32	151	86.34
21018	24.92	143	72.82	982	56
21019	23.33	56	22.01	131	1.43
21020	132.01	965	118.65	145	276.33
21022	47.23	349	33.9	440	6.77
21023	141.27	617	112.32	880	223.75
21024	43.87	553	49.76	2630	50.76
21025	38.28	61	74.78	938	9.48
21026	98.43	292	13.32	91	218.4
21027	114.42	859	96.79	446	189.47
21028	48.28	804	46.63	776	63.26
21029	115.8	777	186.13	1391	278.54
21031	42.25	459	36.8	576	56.23
21032	66.45	161	31.41	230	12.4
21033	53.74	203	49.09	588	34.69
21035	51.78	1328	25.3	851	39.12
21036	66.32	283	60.93	246	41.6
21037	75.87	706	82.63	636	48.65
21038	93.02	201	15.95	170	188.42
21039	46.02	1108	52.39	1382	97.43
21040	40.63	566	54.35	510	3.82
21041	70.4	544	41.64	214	36.6
21043	42.08	138	52.61	342	106.6
21045	49.17	1086	94.11	753	8.99
21046	49.54	441	93.19	857	11.6
21047	102.51	107	93.21	1423	171.4
21048	73.06	346	109.36	45	69.34
21049	82.87	437	77.59	421	52.23
21050	57.43	48	81.35	270	32.42
21051	134.11	808	104.68	308	263.4
21052	88.56	407	138.8	531	38.2
21054	18.37	47	42.5	947	3.68
21055	85.87	283	44.98	218	114.68
21057	115.96	460	187.68	811	197.56
21058	63.64	214	45.38	265	41.73
21059	22.97	203	88.58	874	99.4
21060	35.86	661	119.6	232	5.77
21061	64.06	658	74.84	177	40.84
21062	62.96	351	61.97	1370	45.5

1. The Recommended Dietary Allowance for Vitamin A is approximately 800 mcg for most individuals.Make a two-by-two table depicting how many individuals meet or exceed (greater than or equal to) the requirement when using data from the first 24-hour recall compared to the second 24-hour recall. Calculate crude agreement and Kappa and comment on the agreement between the two 24-hour recalls. (Note: do not calculate sensitivity, specificity, positive predictive value, etc.)

		Day 2
		Meet/Exceed RDA	Do Not Meet/ Exceed RDA	Total
Day 1	Meet/Exceed RDA
Do Not Meet/ Exceed RDA
	Total

1. The upper limit of the Acceptable Micronutrient Distribution Range for fat intake is 35% of total kilocalories for most individuals. For an individual consuming a 2,000-kilocalorie diet, that is approximately 75 grams of fat. make a two-by-two table depicting how many individuals meet or exceed (greater than or equal to) the requirement when using data from the first 24-hour recall compared to the second 24-hour recall. Calculate crude agreement and Kappa, then comment on the agreement between the two 24-hour recalls.(Note: do not calculate sensitivity, specificity, positive predictive value, etc.)

		Day 2
		Meet/ Exceed AMDR	Do Not Meet/ Exceed AMDR	Total
Day 1	Meet/Exceed AMDR
Do not meet/ Exceed AMDR
	Total

Crude agreement? Day 2 Crude agreement: Group I Group 2 Total What is the total that were grouped Group I A B identically on day 1 Day I & day 2? Group 2 C D Total = A + D Percent agreement Total = A+D / A+B+C+DCrude agreement - Proportion classified similarly by two assessment methods Crude agreement: Total= _35_+ _ Total = _ Proportion: =0.61 Kappa Statistic - Proportion classified similarly by two assessment methods, after accounting for chance agreement Steps: Tutorial: Video Example 1. Calculate Po (the observed proportional agreement) Po-Pe 2. Calculate Pe (the probability of random agreement) 1- Pe 3. Insert your calculations into the formula and solveKappa Statistic Step 1: Post Calculate Po (the observed proportional agreement) Mostly cooked Did not Total Po = proportion in agreement/total at home Mostly Po = 35+111_/ 238 cooked at 35 25 60 Pre home Po = 146/238 Did not 67 III 178 Po = 0.61 Total 102 136 238Kappa Statistic Step 2: Calculate Pe (the probability that the measures would randomly agree) P1: Probability of being in group 1 (energy req met) P2: Probability of being in group 2 (not met) P1 = Day 1 proportion in group 1*Day 2 proportion in group 1 P1= (_60 /_238 )*(_102_/_238_) = 0.11 P2=( 178 /_238 )*(_136 /_238 ) = _0.43 Pe = P1 + P2 = 0.11 + 0.43 = 0.54Kappa Statistic Step 3: Calculate kappa statistic by inserting values into formula K = (Po - Pe)/(1-Pe) Po -Pe K = (_0.61_-_0.54_)/ (1 - _0.54_) k= k = 0.17 1-PKappa Statistic Interpretation 0 Agreement equivalent to chance 0.1 =0.20 Slight agreement 021 =0.40 Fair agreement 0.4] =0.60 Moderate agreement 0.6]1 0.80 Substantial agreement 0.81 =0.99 Near perfect agreement Perfect agreement