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Page 1 of 15 Name ____Vanessa Sanchez

NUR 627: Advanced Epidemiology and Biostatistics for Nursing

Assignment 2; DUE AR!" #$% 2$# 6

This test includes two sections.

== The FIRST SECTION includes 19 questions

== The SECOND SECTION includes 7 questions related to anal!in" and inter#retin" the data.

Download and use the $ile %sale'data'(ssi"n&ent)'S#rin".sa*+

&'e total score is () points *2$+ of t'e grade,-

Na&e the $ile with our %last na&e+ and attach the $ile to ,lac-,oard in % Assignment2+ or e&ail

the answers to &a"dashaheencdrewu.edu , (.#$.2$#6

1. /hat is a T#e I error0 i*e e2ale 3T/O 4OINTS5

T#e I error6 False #ositi*e error. This occurs when the null h#othesis is true ,ut was re8ectedas $alse , the testin".

E2ale The (l#ha6Feto#rotein :(F4; Test screens the &otherarital status No&inal6 qualitati*e ,ecause it has no order.

?. /hat t#e o$ statistics can ,e used to descri,e the *aria,les $astin" "lucose le*el #ain

scale score and &arital status0 3TREE 4OINTS5

Fastin" "lucose le*el arametric . for e/ample% a t0o sample &. &est-

mailto:[email protected]:[email protected]

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4ain scale score Non parametric . for e/ample% a 1'i 3uare or correlation coefficient test-

>arital status Non parametric . for e/ample 1'i 3uare or correlation coefficient test.

@. /hat is T#e II error0 i*e e2ale 3T/O 4OINTS5

/hen the null h#othesis is $alse and ou $ail to re8ect it ou &a-e a t#e II error. The

#ro,a,ilit o$ &a-in" a t#e II error is A which de#ends on the #ower o$ the test. Bou can

decrease our ris- o$ co&&ittin" a t#e II error , ensurin" our test has enou"h #ower.

Bou can do this , ensurin" our sale si!e is lar"e enou"h to detect a #ractical di$$erence

when one trul e2ists.

E2ale ( &edical researcher wants to coare the e$$ecti*eness o$ two &edications.

Null h#othesis The two &edications are equall e$$ecti*e.

The researcher concludes that the &edications are the sa&e when in $act the are di$$erent.

This could #otentiall ,e li$e threatenin" i$ the less e$$ecti*e &edication is sold to the

#u,lic.

. t statistics = 6?.) and #6*alue=.? descri,e the di$$erence ,etween wo&en and &en $or

&ental health score. I$ al#ha is set to . is the #6*alue o$ .? statisticall si"ni$icant0 In a

sentence inter#ret the # *alue o$ .?. 4ro*ide a rationale $or our answer 3ONE 4OINT5

46*alue is statisticall si"ni$icant.

Rationale Since #6*alue o$ .? is less than al#ha o$ . null h#othesis will ,e re8ected thusit is si"ni$icant

. /as there a si"ni$icant di$$erence in /or-in" status $or the three le*els o$ insurance

:uninsured >edicaid6enrolled and #ri*atel insured; i$ G = )7.?9 # H .10 4ro*ide a

rationale $or our answer. 3ONE 4OINT5

Rationale There is a si"ni$icant di$$erence ,etween wor-in" status $or the three le*els o$

insurance :uninsured >edicaid6enrolled and #ri*atel insured;. Since #6*alue $or the calculated

chi square is less than . we re8ect null h#othesis there$ore this is statisticall si"ni$icant.

7. Does a set o$ scores with &ost o$ its *alues a,o*e the &ean ha*e a ne"ati*el or #ositi*el

s-ewed distri,ution0 4ro*ide a rationale $or our answer. 3ONE 4OINT5

Rationale It would ha*e a ne"ati*el s-ewed distri,ution. This is ,ecause &ost o$ its *alues are

a,o*e the &ean a##earin" as a lon" le$t tail in the ne"ati*e direction on the nu&,er line. The

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&ean is #ulled in the direction o$ the e2tre&e scores so in this scenario the e2tre&e scores are

lar"er thus the &ean is lar"er than the &edian and to the le$t o$ the #ea-.

. ( stud $ound that the correlation %r+ *alue $or the relationshi# ,etween $astin" "lucose le*el

and the len"th o$ sta in the hos#ital is .) and #6*alue was .). I$ al#ha is set to ,e . is

this %r+ *alue o$ .) statisticall si"ni$icant0 Inter#ret the %r+ *alue 3STRENT (NDDIRECTION5 and #ro*ide a rationale $or our answer. 3T/O 4OINTS5

%r+ *alue o$ .) is statisticall si"ni$icant.Rationale %r+ *alue ran"es $ro& 61 to 1 and the "reater the a,solute *alue o$ the correlation

coe$$icient the stron"er the linear relationshi#. The *alue o$ r in this case :r = .); indicates that

there is a #ositi*e linear relationshi# o$ &oderate stren"th ,etween $astin" "lucose le*el and thelen"th o$ hos#ital sta. (lso #6*alue o$ .) is less than al#ha o$ . so we re8ect null

h#othesis there$ore it is statisticall si"ni$icant.

9. I$ the researchers had set the le*el o$ si"ni$icance or al#ha=.1 would the results o$ #=.1

still ,e statisticall si"ni$icant0 4ro*ide a rationale $or our answer. 3ONE 4OINT5

Bes the #6*alue o$ .1 would still ,e statisticall si"ni$icant ,ecause it is less than the al#ha o$

.1 which would result in a re8ection o$ the null h#othesis ,ecause the #6*alue is s&aller thanthe set rate o$ the al#ha.

Jse the $ollowin" #ara"ra#h to answer the ne2t two questions

The $ollowin" re$ers to questions 1 and 11.

( researcher rando&i!es 7 coronar arter disease :C(D; #atients to either >edicine ( or

>edicine K. The outco&e o$ interest is &ocardial in$arction :>I;. In the statistical section o$

the #u,lished #a#er the researcher writes that al#ha was set at . and 7 #atients were

required to achie*e L #ower to detect a di$$erence o$ 1L or &ore ,etween the two stud

ar&s. The researcher re#orts that )L o$ the #atients on >edicine ( had an >I while 7L o$

#atients on >edicine K had an >I with # = .?.

1. Is the stud result statisticall si"ni$icant0 4ro*ide rationale 3ONE 4OINT5

This stud result is statisticall si"ni$icant related to the $act that the # *alue o$ .? is less than

the al#ha *alue o$ .. This deter&ines that there is a di$$erence in #atients with C(D ,etween&edicine ( and &edicine K. There$ore a # *alue o$ .? is less than the al#ha *alue o$ .

&a-in" this a null h#othesis that should ,e re8ected and an alternati*e h#othesis ,e considered.

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11. /rite a sentence that inter#rets the # *alue o$ .? in relation to the stud results. Jse .? in

our sentence. 3ONE 4OINT5

( 46 Malue o$ .? &eans that there is a 97L chance that the di$$erence in outco&es is directl

related to the di$$erent &edications :>edications ( and K;.

Select one answer $or the $ollowin" questions and 8usti$ our answer :i.e. wh ou

select a s#eci$ic answer;

1). /hat is the statistical test :#rocedure; that is used to deter&ine whether a si"ni$icant

di$$erence e2ists ,etween three or &ore "rou# &eans0 3ONE 4OINT5

(; t6test

K; (NOM(

C; Correlation coe$$icient

D; >ann /hitne J test

Rationale: The (NOM( test is used to test di$$erences in three or &ore "rou# &eans or&eans $or two or &ore inde#endent *aria,les.

1?. /hat t#e o$ h#othesis is re#resented , the state&ent %wo&en who s&o-e are asli-el to ha*e low6,irth6wei"ht ,a,ies as wo&en who do not+0 3ONE 4OINT5

(; (lternati*e h#othesis

K; Non6directional

C; Research

D; Null h#othesis

Rationale: This t#e o$ theor is one that has ,een #ut $orward either ,ecause it is ,elie*ed it is true or ,ecause it is used as a ,asis $or an ar"u&ent ,ut has not ,een

#ro*ed.

1@. The nurse researcher is calculatin" the standard de*iation. /hat is the standard

de*iation0 3ONE 4OINT5

(; The a*era"e a&ount o$ de*iation o$ *alues $ro& the &ode and is calculated $or

e*er other scoreK; The a*era"e a&ount o$ de*iation o$ *alues $ro& the &edian and is calculated $or

e*er other score

C; The a*era"e a&ount o$ de*iation o$ *alues $ro& the &ean and is calculated $or

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e*er score

D; The a*era"e a&ount o$ de*iation o$ *alues $ro& the &edian and is calculated $or

e*er score

Rationale: The tandard Deviation is a &easure o$ how s#read out nu&,ers are. Its s&,ol

is :the "ree- letter si"&a; The $or&ula is the square root o$ the Mariance.

1. /hat test would a nurse researcher use to test h#otheses a,out "rou# di$$erences in

#ro#ortions0 3ONE 4OINT5

(; t6test

K; (NOM(

C; Correlation coe$$icient

D; Chi6square

Rationale: The Chi6squared test can ,e used to test di$$erences in #ro#ortions ,etween two or

&ore "rou#s

1. The inde#endent *aria,le is wei"ht "ain durin" #re"nanc. The de#endent *aria,le is the

in$ants ,irth wei"ht. /hat is the a##ro#riate test statistic0 3ONE 4OINT5

(; t6test

K; (NOM(

C; Chi6square

D; 4earsons r

Rationale: It is the &easure o$ direction and stren"th o$ inde#endent *aria,le wei"ht "ain durin"

#re"nanc and a de#endent *aria,le in$ant

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C; Mariance

D; >ean square

Rationale The standard error o$ the &ean :SE>; is the standard de*iation o$ a salin"

distri,ution. It esti&ates the *aria,ilit ,etween sale &eans $ro& &ulti#le sales $ro& thesa&e #o#ulation. SE> is also a "ood &easure&ent in deter&inin" how #recise the &ean o$ the

sale esti&ates the #o#ulation &ean. The lower the SE> *alue the &ore #recise the esti&ates

o$ the #o#ulation &ean and *ice *ersa.

1. /hat is the na&e $or the sha#e o$ distri,ution that occurs when the nurse researcher has a ,ell6sha#ed cur*e distri,ution0 3ONE 4OINT5

(; Frequenc

K; Jni&odal

C; >ulti&odal

D; Nor&al

Rationale: Nor&al distri,utions are usuall s&&etrical with a sin"le central #ea- at the &ean

o$ the data :uni6&odal;. The are neither $lat nor s-ewed. There$ore a nor&al distri,ution has a

,ell6sha#ed cur*e. (ll nor&al distri,utions or cur*es share the sa&e #ro#erties where L o$the o,ser*ations lie within 1 standard de*iation o$ the &ean 9L lie with ) standard de*iations

o$ the &ean and 99.7L o$ the& lie within ? standard de*iations o$ the &ean.

19. /hat #ara&etric statistical &ethod:s; a researcher can use to deter&ine i$ the &ean

,od &ass inde2 o$ the #o#ulation is the sa&e $or two "rou#s o$ su,8ects :"rou#1=diet

restrictionQ "rou#)=none;. :E(C IS ONE 4OINT =TOT(=TREE 4OINTS;

(. Statistical test is a )6 sale t6test. It used to deter&ine whether the &eans o$

two inde#endent "rou# di$$ers. It

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(nswer the $ollowin" questions

1. Do $requenc $or the $ollowin" *aria,les and inter#ret the $indin"s3FOJR 4OINTS5

("ecat :("e cate"or; ender dia,etes :histor o$ dia,etes; dhos# :died in hos#ital;.

Rationale:

("e cate"or ?.L are ,etween the a"es 6@ ears old. This is the hi"hest #ercenta"e o$ the

"rou#. 1).?L are 7 and older and this is the lowest #ercenta"e , a"e.

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ender .L are &ale and @9.L are $e&ale.

istor o$ dia,etes 1). L are dia,etics and 7L ha*e no histor o$ dia,etes.

Died in hos#ital .L o$ the #o#ulation $ro& this stud is &issin" in$or&ation. For the rest o$the results )?.7L died in the hos#ital and 7.7L did not die in the hos#ital.

). Do descri#ti*e statistics and histo"ra& with nor&al distri,ution and inter#ret the results

$or the $ollowin" *aria,les 3TREE 4OINTS5

os'reha, :len"th o$ sta $or reha,ilitation; cost :total treat&ent and reha,ilitation costs

in thousands; and $astin"'"lucose'le*el :$astin" "lucose le*el;

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Descriptive Statistics

N Minimum Maximum Mean Std. Deviation

Statistic Statistic Statistic Statistic Std. Error Statistic

Total treatment and rehabilitationcosts in thousands

1048 2.12 126.6 2.!!6 .""0#2 24.!4402

$en%th o& sta' &or rehabilitation "8" 0 6 16.! .448 12.#6#

&astin% %lucose level 1048 "0 16# 110.4# .4!1 1#.8!"

(alid N )list*ise+ "8"

The histo"ra& $or len"th o$ sta $or reha,ilitation is uni&odal s&&etrical with a wide s#read ran"in"

$ro& das to ? das. The &ean was 1.?9 das with a standard de*iation o$ 1).. The histo"ra& $or

total treat&ent cost is uni&odal and #ositi*el s-ewed with a &ean o$ ?).9 thousand dollars and standardde*iation o$ )@.9@. Fastin" "lucose le*el has s&&etrical and uni&odal histo"ra& with a wide ran"e o$

7U1 &ean o$ 11.@ and standard de*iation o$ 1.9.

?. Is there a di$$erence ,etween those who died in the hos#ital and those who did not die in

the hos#ital in the $ollowin" *aria,les6 a"e :a"e at ad&ission in ears; 3ONE 4OINT56 $astin" "lucose le*el 3ONE 4OINT5

a. /hat statistical test ou will use0

Inde#endent Sales T6Test will ,e used to deter&ine the statistical di$$erence ,etween

related "rou#s

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,. Is the di$$erence ,etween the two "rou#s statisticall si"ni$icant0 E2#lain and

inter#ret the $indin"s

Kased on 9 su,8ect stud 71 su,8ects did not die in the hos#ital while )@ su,8ects died in

the hos#ital. The &ean $or those who did not die in the hos#ital is 1.? with a SD o$ .79?

while the &ean $or su,8ects who died in the hos#ital was ?.@?. The &ean $or $astin" ,lood su"ar $or those who died in the hos#ital is 11.? and 11.7 $or those that didn

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,; Is the di$$erence statisticall si"ni$icant0

E2#lain and inter#ret the $indin"

rou# 1 :Fastin" "lucose le*el and ("e cate"or; The di$$erence is statisticall insignificant

,ecause the #6*alues o$ .1 and .11 are "reater than . there$ore we don

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The correlation coe$$icient r is a &easure o$ the direction and stren"th o$ a relationshi# that

ran"es $ro& 61 to P1. (ccordin" to the correlation r *alues as dis#laed under %4earson

Correlation+ &ost o$ the relationshi#s in the &atri2 are o$ weak correlation with low correlation

r *alues in the positive direction at .1@ .1 . etc. The #ositi*e directions in theserelationshi#s indicate that there are hi"her 2 *alues than in wea- linear relationshi#s. On a

scatter#lot the data would loo- scattered and show so&ewhat #ositi*e linear relationshi#s ,ut

the correlations would not &ean &uch.

Thou"h it is also worth &entionin" that there is a moderate correlation o$ .11 in the positivedirection ,etween len"th o$ sta $or reha,ilitation and total treat&ent and reha,ilitation costs.

This &eans that there is a &oderate linear relationshi# ,etween the ) *aria,les. This #ositi*ecorrelation also &eans that as the len"th o$ sta $or reha, increases the total costs would &ost

li-el increase as well.

. (re there relationshi# ,etween #atient

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b) K# :Klood #ressure;. 3ONE 4OINT5

a. /hat statistical test ou will use0

4earson Chi6Square Test

,. Is an o$ these relationshi#s

statisticall si"ni$icant0

i. I$ es which relationshi#0

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Koth o$ these chi6square tests show there is no si"ni$icance ,etween the nu&,er o$ deaths in the

hos#ital in relation to dia,etes and ,lood #ressure.

ii.E2#lain and inter#ret the $indin"s.

V) :1;= 1.) # W .. Since the # *alue is :.?11; is "reater than al#ha :.; and the null

h#othesis is retained. This concludes there is no si"ni$icant relationshi# ,etween the histor o$dia,etes o$ a #atient and the nu&,er o$ deaths in the hos#ital.

V) :);= ).)?9 # W . Since the # *alue is :.?); is "reater than al#ha :.; and the null

h#othesis is retained. This concludes there is no si"ni$icant relationshi# ,etween the ,lood

#ressure o$ a #atient and the nu&,er o$ deaths in the hos#ital.

7. /rite a ONE 4(E su&&ar re#ort $or the results o$ the stud and its iact on nursin"

#ractice :i.e. su&&ari!e the $indin"s $ro& question 1 to ; 3T/O 4OINTS5

The $requenc o$ the *aria,les #ro*ides descri#ti*e in$or&ation a,out the ,ac-"round

characteristics o$ the sale in this stud. In the a"e cate"or ?.L are ,etween 6@ rs oldand 1).?L are 7P a"e cate"or. For the *aria,le o$ "ender .L are &ale and @9.L are$e&ale. There were sli"htl &ore &ales than $e&ales. For the *aria,le o$ histor o$ dia,etes

7.@L ha*e no histor o$ dia,etes and 1).L are dia,etics. The &a8orit 7.@L o$ the sale

did not ha*e a histor o$ dia,etes. For the ,lood #ressure *aria,le .@L ha*e nor&al ,lood

#ressure )7.L ha*e h#ertension and 11.L ha*e h#otension. For #atients who died inhos#ital *aria,le the $requenc indicates we ha*e &issin" in$or&ation on .L o$ the #o#ulation

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o$ the stud "rou# :9 sales;. For the in$or&ation a*aila,le )?.7L died in the hos#ital while

7.7L did not die in the hos#ital.

/ith the use o$ descri#ti*e statistics we are a,le to descri,e and su&&ari!e data relatedto a"e in ears and len"th o$ sta $or reha,ilitation. The a"e ran"e is @1 with &a2i&u& and

&ini&u& @. The &ean a"e is ).@ and SD is 9.11?. The ran"e o$ len"th o$ sta $or

reha,ilitation is ? with &a2i&u& ? and &ini&u& . The &ean is 1.?9 and SD is 1).. The&ean is the ,est sin"le #oint in the distri,ution $or su&&ari!in" a set o$ *alues and the standard

de*iation tells us how &uch on a*era"e the *alues de*iate $ro& the &ean.

The inde#endent t6test was used to e*aluate i$ there was a di$$erence ,etween those whodied in the hos#ital and those who did not die in the hos#ital in a"e. Kased on the data 71 did

not die in the hos#ital and )@ died in hos#ital. The &ean a"e $or did not die in hos#ital is 1.?

with SD o$ .. The &ean a"e $or died in hos#ital is ?.@? with SD o$ 9.7. The t *alue is

6).@19 with standard error di$$erence o$ .1. The # *alue is .1 that is less than .. /ecan re8ect the null h#othesis. There$ore we can conclude that there is a statisticall si"ni$icant

di$$erence ,etween the a"e in ears o$ the indi*iduals who died in the hos#ital and those who did

not die in the hos#ital.

The one6wa (NOM( was used to anal!e the di$$erence ,etween "rou#s o$ ,lood #ressures. The di$$erence is not statisticall si"ni$icant ,ecause # is .@ that is lar"er than the

al#ha . so we $ail to re8ect the null h#othesis. /e ha*e 9L con$idence there is nodi$$erence ,etween the ,lood #ressure "rou#s in a"e.

( correlation is a ,ond or connection ,etween *aria,les. Correlation analsis is use$ul to

descri,e the direction and &a"nitude o$ a relationshi# ,etween two *aria,les. To test i$ there wasa relationshi# ,etween a"e and len"th o$ sta $or reha,ilitation a correlation was couted. The

# is . that is less than al#ha set at .1. /e conclude that the correlation ,etween a"e in

ears and len"th o$ sta $or reha,ilitation is o$ wea- si"ni$icance. The correlation coe$$icient r is

.1@. The correlation ,etween the a"e in ears and len"th o$ sta $or reha,ilitation is in #ositi*edirection and *er wea-.

The chi6square statistical test was used to anal!e i$ there was a correlation ,etween died

in hos#ital and dia,etes then $or died in hos#ital and ,lood #ressure. The correlation coe$$icient ,etween died in hos#ital and dia,etes is .?11. This &eans the correlation ,etween the two

*aria,les is in #ositi*e direction and *er wea-. The correlation coe$$icient ,etween died in

hos#ital and ,lood #ressure is .7. This &eans the correlation ,etween the two *aria,les is inin #ositi*e direction and o$ &oderate stren"th. The # *alue is .?11 $or correlation ,etween died

in hos#ital and dia,etes. The # *alue is lar"er than al#ha set at .1. /e cannot re8ect the null

h#othesis. The relationshi# ,etween died in hos#ital and dia,etes and ,# is not statisticall

si"ni$icant.

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