Statisticsresearch methods
StatisticsResearch Methods
Thedataset used is the Student Health dataset.
Myindependent variable is ‘How many sexual partners have you had inthe last year?’(SexPartner12mos).This is an ordinal variable withthe following responses :
“0”
“1-2”
“3-5”
“6+”
Mydependent variable is ‘Have you been tested for an STD within thelast 12 months?’(STDtest12mos).This is a nominal variable with thefollowing responses:
“Yes”
“No”
Theresearch question in my case is ..Does the number of partners astudent had in the past year determine if the student has been testedfor an STD for the past 12 months
Hypothesis.
Null-H0:There is no association between number of partners a student had inthe past year and if the student has tested for an STD within thelast 12 months.
Alternative– H1:There is an association between number of partners a student had inthe past year and if the student has tested for an STD within thelast 12 months.
Thereason for the alternative hypothesis is because when a person whohas had multiple sexual partners they tend to be at more risk tocontract an STD.This makes the people to be more likely to test foran STD than people who have had few partners over the past oneyearThe other reason is that the STD testing promotions tend toencourage people who had multiple partners to go for testing.Thismentality will lead to a people with more partners over the past yearto be more likely to test for an STD.(Carter, M. , Kraft, J., Hatfield‐Timajchy, K., Hock‐Long, L., & Hogben, M. (2011). Std and hiv testing behaviors amongblack and puerto rican young adults. Perspectiveson Sexual and Reproductive Health,43(4),238-246.)
Theinferential statistical test used to test our hypothesis is thePearson’s chi-square test.This is because our dependent variable isa nominal variable and the independent variable is an ordinalvariable.This means that our two variables contain categorical datahence the necessity to use the person’s chi-square test as ourinferential statistical test.Our dependent variable which was ‘Haveyou been tested for an STD within the last 12 months?’(STDtest12mos)was treated qualitatively.
How many sexual partners have you had in the last year? | |||||
  | Frequency | Percent | Valid Percent | Cumulative Percent | |
Valid | 0 | 22 | 13.8 | 13.8 | 13.8 |
1-2 | 118 | 74.2 | 74.2 | 88.1 | |
3-5 | 17 | 10.7 | 10.7 | 98.7 | |
6+ | 2 | 1.3 | 1.3 | 100.0 | |
Total | 159 | 100.0 | 100.0 |   | |
Descriptivestatistics
Table1:
Fromtable above we had a total number of 159 students in our sample. Ofthis 22(13.8%) had 0 partners in the last year, 118(74.2%) had 1-2partners in the last year ,17(10.7%) had 3-5 partners in the last while 17(10.7%) had 6 or more partners in the last year.Majority ofthe students had 1-2 partners in the last year while very fewstudents had 6 or more partners in the last year
Table2:
Have you been tested for an STD within the last 12 months? | |||||
  | Frequency | Percent | Valid Percent | Cumulative Percent | |
  | Yes | 71 | 44.7 | 44.7 | 44.7 |
No | 88 | 55.3 | 55.3 | 100.0 | |
Total | 159 | 100.0 | 100.0 |   | |
Fromtable above of the 159 students in our sample 71(44.7%) said they hadbeen tested for an STD within the last 12 months while 88(55.3%) said they hadn’t tested for an STD within the last 12 months.Thisindicates that majority of the students hadn’t tested for an STDwithin the last 12 months.
Table3
Demographic: What is your gender? | |||||
  | Frequency | Percent | Valid Percent | Cumulative Percent | |
Valid | Male | 24 | 15.1 | 15.1 | 15.1 |
Female | 135 | 84.9 | 84.9 | 100.0 | |
Total | 159 | 100.0 | 100.0 |   | |
Fromtable above our sample consisted of 24(15.1%) male students and135(84.9%) female students.The majority of the students in our samplewere female.
Table4:
Demographic: What is your relationship status? | |||||
Frequency | Percent | Valid Percent | Cumulative Percent | ||
Valid | Single | 142 | 89.3 | 89.3 | 89.3 |
Married | 16 | 10.1 | 10.1 | 99.4 | |
Divorced | 1 | .6 | .6 | 100.0 | |
Total | 159 | 100.0 | 100.0 | ||
Therewere 159 students in our sample. majority of the students were single142(89.3%),while the married students were 16(10.1%) and only 1(0.6%)student was divorced.
Table5:
Demographic: What is your race/ethnicity? | |||||
  | Frequency | Percent | Valid Percent | Cumulative Percent | |
Valid | White/Caucasian | 69 | 43.4 | 43.4 | 43.4 |
Black/African American | 3 | 1.9 | 1.9 | 45.3 | |
Native Hawaiian/Pacific Islander | 2 | 1.3 | 1.3 | 46.5 | |
American Indian/Alaskan Native | 1 | .6 | .6 | 47.2 | |
Latino | 13 | 8.2 | 8.2 | 55.3 | |
Hispanic | 42 | 26.4 | 26.4 | 81.8 | |
Asian | 21 | 13.2 | 13.2 | 95.0 | |
Other | 8 | 5.0 | 5.0 | 100.0 | |
Total | 159 | 100.0 | 100.0 |   | |
Outof the 159 students in our sample 69(43.4%) werewhite/Caucasian,3(1.9%) were Black/African American,2(1.3%) wereNative Hawaiian/Pacific Islander, 1(0.6%) were AmericanIndian/Alaskan Native, 13(8.2%) were Latino, 42(26.4%) wereHispanic,21(13.2%) were Asian while students of the other races were8 (5%). Majority of our students in the sample were white/Caucasianwhile we had the least students 1 (0.6%) of American Indian/AlaskanNative race.
Figure1:
Thereason for choosing a bar chart to represent gender is because of thefew categories of gender variable and the need to represent thegender variable in percentages.
Fromfigure 1 we can see that in our sample students 84.9% were female and15.1% were male.
Figure2:
Thereason I chose the bar graph to represent the sex partners studentshad in the last year is because it is easier to compare thepercentage of students in each group of the number of partnersstudents had and easy to see the trend across the groups(Wickham, 2009)
FromFigure 2 we can tell that 13.8% of the students had no partner in thelast year ,74.2% of the students had 1-2 partners in the lastyear,10.7% of the students had 3-5 parners in the last year andlastly 1.3% of the students had 6 or more partners in the last year.
Table6.
Chi-Square Tests | |||
  | Value | df | Asymp. Sig. (2-sided) |
Pearson Chi-Square | 15.728a | 3 | .001 |
Likelihood Ratio | 17.743 | 3 | .000 |
Linear-by-Linear Association | 15.470 | 1 | .000 |
N of Valid Cases | 159 |   |   |
a. 2 cells (25.0%) have expected count less than 5. The minimum expected count is .89. | |||
Fromtable 6 the P-value=0.001 which is less than 0.05 hence we rejectthe null hypothesis.
Aperson chi square test was conducted to determine if there was anassociation between the number of partners a student had in the pastyear and if the student has been tested for an STD for the past 12months. The association between the two variables was significant,X2(3,N=159)=15.728,P=0.001<0.05.
Thismeans that the more partners a student had in the last year the morelikely he/she was to be tested for an STD within the past 12 months.
Thisresults were as I expected as the more partners a person has he willtend to be more likely to take an STD test since the studentsbelieves he is more exposed to the risk of contracting an STD.
References
Wickham,H. (2009). ggplot2:elegant graphics for data analysis.Springer Science & Business Media.