PUH 5302, Applied Biostatistics 1

Course Learning Outcomes for Unit VIII

Upon completion of this unit, students should be able to:

3. Evaluate study designs and statistical tests for public health research and analysis. 3.1 Compare and contrast various types of tests used in nonparametric methods. 3.2 Analyze the use of data visualization methods in public health.

Course/Unit Learning Outcomes

Learning Activity

3.1 Unit Lesson Chapter 10 Unit VIII Assessment

3.2 Unit Lesson Chapter 12 Unit VIII Assessment

Reading Assignment

Chapter 10: Nonparametric Tests

Chapter 12: Data Visualization

Unit Lesson

Welcome to Unit VIII. In the previous unit, we learned how to analyze public health information and interpret results of biostatistical analysis. We also defined examples of the dependent and independent variables and closed with a discussion on multivariable methods.

In this unit, we will discuss how to select appropriate study designs and statistical methods for public health. In doing so, we will compare and contrast various methods used in nonparametric statistics and close with some information on data presentation and visualization methods.

Nonparametric Methods

Statistical methods have different forms of classifications such as descriptive and inferential statistics and parametric and nonparametric methods, to list a few. We will concentrate on nonparametric methods, but let’s briefly review some points about parametric methods.

 Parametric methods work best with normally distributed populations (or close to normal populations).

 They use two parameters to achieve normal distributions, namely mean and standard deviation.

 They rely on assumptions made about a given population such as confidence interval for a population with known and unknown standard deviation, confidence interval for a population variance, and confidence interval of two means with unknown standard deviation.

In contrast with parametric methods, nonparametric methods do not have to make any assumptions about the population under study. They do not have any dependence on population under study, do not have fixed parameters, and are distribution-free methods. Many researchers have shown interest in nonparametric methods because, aside from the characteristics described above, they are easy to apply and understand, and they do not have any constraints.

UNIT VIII STUDY GUIDE

Selecting the Appropriate Study Design

PUH 5302, Applied Biostatistics 2

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Comparing Parametric and Nonparametric Methods (Summary)

 Parametric statistics depend on normal distribution, but nonparametric statistics do not.

 There are less assumptions made in parametric than nonparametric statistics.

 Parametric statistics use simpler formulae in comparison to nonparametric statistics.

 Parametric statistics are used for normal or close to normal distribution. Nonparametric methods are used for data that are not normally distributed.

 Parametric statistics are commonly used in preliminary data analysis, while nonparametric statistics are not used as often and generally only apply to special cases (Sullivan, 2018).

Applications of Nonparametric Methods Nonparametric methods are mostly used in studies involving populations with attributes that can be ranked. Data that can be ranked with no clear numerical underpinnings or interpretations are normally used in nonparametric analysis. Ordinal data are examples of such. Nonparametric methods are applied widely because they make fewer assumptions about the population under study. In addition, because there are fewer assumptions, they facilitate robust statistics by seeking to provide methods that follow popular statistical methods. However, one of the differences is that nonparametric methods are not affected by outliers or values that are plus or minus a few departures from the mean. Nonparametric methods have been associated with simplicity because they save the researcher from committing to other analyses to justify the use of parametric methods. However, this simplicity may serve as a weakness in that, in cases where a parametric test would be appropriate, the researcher may decide to choose the parametric method over the nonparametric method. Types of Data and Tests Used in Nonparametric Statistics Nonparametric statistics are used on nominal or ordinal data or scales of measurement. The table below gives you a summary of the type of tests used in nonparametric testing. The Chi-square statistics and their modifications are used for nominal data. All other nonparametric statistics are appropriate only when data are measured on an ordinal scale of measurement. See table below for examples of the different tests used for nominal and ordinal data.

Nominal Data Ordinal Data

Chi-Square Goodness-of-Fit Test Mann-Whitney U Test

Chi-Square Test of Independence Wilcoxon Signed Rank Test

McNemar’s Test Kruskal-Wallis Test Friedman Two-way Analysis of Variance (ANOVA) by Ranks Test Spearman rs

For a more comprehensive look at some of the tests above as well as other nonparametric tests read the information below:

 The Chi-Square Goodness-of-Fit is a nonparametric test deployed to establish the significant difference between the observed value and the expected value. It helps to discern how the theoretical value fits the calculated value. It is most used to compare samples involving intervals.

 The Fisher Exact Probability is used to test the statistical significance in certain samples of data. It falls in one of the classes of exact tests because the exact significance of the deviation from the null hypothesis can be calculated instead of approximated. The Fisher Exact Probability test is useful for categorical data to examine the significance of the association between the two categories.

 The Mann-Whitney U test is the nonparametric counterpart of the parametric t-test. It does not require a normal distribution for its calculation, and it is equally effective as the t-test. In order to calculate the Mann-Whitney U test, some assumptions must be made: All observations are independent, they have ordinal data, distributions are equal for null hypothesis, and distributions are not equal for the alternative hypothesis. With these assumptions, the researcher can effectively conduct the test with reliable results.

 The Wilcoxon Signed-Rank test is a nonparametric test used in evaluating the differences in two groups that are correlated. The basic requirement for using this test is that the data must be matched,

PUH 5302, Applied Biostatistics 3

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the dependent variable must be continuous, and there should be no ties between the samples. It mostly works with the median of data samples.

 The Kruskal-Wallis test is the nonparametric test for its parametric counterpart, analysis of variance (ANOVA). The two tests are used to examine significant differences between a continuous variable and a categorical variable. The continuous variable must be the dependent variable, and the categorical variable must be the independent variable with two or more groups. Unlike ANOVA, where assumptions of normality are assumed for the dependent variable, the Kruskall-Wallis test does not have such assumptions.

 The Friedman Two-way Analysis of Variance (ANOVA) by Ranks test is also a nonparametric test similar to ANOVA and is used to examine differences across multiple samples using ranking. It is similar to the Kruskal-Wallis test.

 The Kolmogorov-Smirnov test attempts to determine if two datasets are significantly different. It is a distribution-free test and makes no assumption about the distribution of the data. The Kolmogorov- Smirnov test may serve another purpose. It can be modified to function as a goodness-of-fit test, but it has been found to be less powerful in its function as a test for normality compared to other tests.

 The Anderson-Darling test is a modification of the Kolmogorov-Smirnov test and is more powerful. The Anderson-Darling test uses specific distribution to calculate critical values and is more sensitive, making it an advantageous test. The limitation to the test is that it requires calculation of the critical values for each distribution.

In order to choose any of these tests for analysis, we must examine our samples in terms of number and relationship between variables. That is, the researcher must conduct exploratory data analysis or prepare the data for testing. Nonparametric tests, as opposed to parametric tests, use ranking. As an example of ranking, let’s examine the pain scale. The pain scale is often measured from 0 to 10, with 0 representing no pain and 10 representing agonizing pain. Sometimes pain scales use visual anchors such as smiling or crying faces that rank the intensity of the pain. Nonparametric testing uses ranks to compare data without taking the normality of the data into consideration. Let’s now examine the various steps in nonparametric testing. Steps in Nonparametric Testing Like parametric testing (discussed in Chapter 7), the nonparametric testing follows the same five steps of hypothesis testing. Please see page 227 of your textbook for further discussion of these steps. Data Visualization Data visualization is a graphical representation of information communicated to an audience. The information is encoded into visual graphics including charts, lines, and bar graphs. The goal here is to help the researcher communicate information clearly and effectively via graphical means that should stimulate the viewer’s attention (Sullivan, 2018). Recipients of the results of scientific findings need clear and accurate reporting of data and statistical results. These graphic presentations may help to generate interest and provoke the thoughts of the audience. Different Formats of Graphical Presentations Information is presented in different formats including texts, tables, figures, and pie charts. Chapter 12 in the textbook gives a clear picture of each of these various formats. One thing that is common with all of these formats is that they must be labeled effectively to provide meaning and interpretation centered on the information they represent. The chart below gives some of the characteristics of these various formats.

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Texts Tables Figures

 A few numbers

 Data that are secondary or ancillary to main analysis

 Many data points to present and exact values

 Main findings (often readers turn to tables before reading text)

 Complex relationships among variables

 Trends over time

 Geographic variation

 Main findings (often readers turn to figures before reading text)

(Sullivan, 2018)

Importance of Data Visualizations To the researcher and the consumer, data visualization is significant because it aids the quick absorption of information. It also helps to save time by looking at the big picture instead of pieces of information and shows patterns and trends in the data. Many consumers have become interested in reading research findings or materials that are presented in graphical forms because the graphical nature of the material helps hold their interest longer. Furthermore, data visualization makes data more accessible and less confusing and helps the researcher share his or her insights with everyone. In many cases, data visualization quickly reveals the outliers in the data and helps researcher or presenters memorize the important insights (Tandon, 2017). Summary Statistical analysis is key to researchers and consumers of the reports advanced from scientific studies. Two main forms of scientific data analysis commonly used in research are parametric and nonparametric methods. Both the parametric and nonparametric follow the same pattern when it comes to data analysis. However, the major difference lies with nonparametric methods not requiring normality of data for analysis. The results of these analyses are sometimes best presented in visual forms for easy and clear presentation to the consumer.

References Sullivan, L. M. (2018). Essentials of biostatistics in public health (3rd ed.). Burlington, MA: Jones & Bartlett

Learning. Tandon, D. (2017, March 14). The Importance of data visualization in your business and 10 ways to pull it off

easily [Blog post]. Retrieved from https://thekinigroup.com/importance-data-visualization/

AHS 619: Advanced Program Planning and Coordination Spring 2020

Annotated Bibliography 10 total points

What is an Annotated Bibliography? An annotated bibliography is a list of citations to books, articles, and other resources. Each citation is followed by a brief descriptive and evaluative paragraph: the annotation. The purpose of the annotation is to inform the reader of the relevance, accuracy, and quality of the sources cited and to help you organize your materials prior to writing your research paper. Check out Purdue OWL for examples: https://owl.english.purdue.edu/owl/resource/614/03/ (review only the APA-style sample).

Requirements for Content: For this part of the assignment, you will create an APA-style annotated bibliography containing a minimum of ten credible sources published between 2013 and 2020.

Creating an annotated bibliography calls for the application of a variety of intellectual skills: concise writing, succinct analysis, and informed library research. You will be reviewing scholarly journal articles and other credible sources relevant to your selected topic. You will create citations for these resources using APA format. You will write concise annotations that summarize the central theme and scope of the articles. These annotations must be approximately 100-150 words and include one or more sentences that:

1. Summarize the article in your own words. DO NOT copy and paste directly from the abstract or article. This is always considered plagiarism!

2. Compare or contrast this work with others you have cited in this assignment 3. Discuss how this work relates to your selected topic 4. As you will be locating current health information, please note that your ten (minimum)

required credible sources must have been published between the years 2013-2020.

Requirements for Formatting:

• An APA-style title page must be included • Citations must be alphabetized by the last name of the first author. • Citations and annotations must be double-spaced (see APA-style sample at:

https://owl.english.purdue.edu/owl/resource/614/03/ • Use 1” margins all around • Use Times New Roman, Calibri or Arial 12-point font

Information about APA Style and Scholarly References: For APA style, pay attention to the left-side menu (how to correctly cite in-text; formatting a reference page, etc.) at this site: http://owl.english.purdue.edu/owl/resource/560/01/ Some helpful information about finding credible, scholarly references include:

http://libguides.indstate.edu/content.php?pid=175498&sid=3038787. Information about credible journal articles: http://lib.colostate.edu/howto/evaljrl2.html

Grading Rubric:

Criterion Not done/poorly done

Acceptable but room for improvement

Well done

Includes a minimum of ten APA-style citations for credible sources published between 2013-2020. Also, adheres to specific formatting/layout guidelines

0-1 2 3

Summarizes each article in your own words

0-1 2 3

Compares or contrasts this work with others you have cited & discusses how this work relates to topic and target population

0-1 1.5 2

Correct grammar, spelling, sentence structure, other mechanics.

0-1 1.5 2

Total: __/10 points

STATEMENT OF POLICY

Syringe Services Programs

Policy The National Association of County and City Health Officials (NACCHO) supports a comprehensive, evidence- based approach to syringe services programs, also known as syringe or needle exchange programs, in order to support the health of people who inject drugs and to curb transmission of HIV, viral hepatitis, and other blood- borne diseases. NACCHO urges state and local policy makers to do the following:

• Support syringe services program development and operation in accordance with the peer-reviewed evidence base, best practices, and local health department and other expert recommendations;

• Remove legal barriers to accessing and safely disposing sterile needles, syringes, and other injecting equipment;

• Modify state and local statutes to permit over-the-counter pharmacy sales and purchase of syringes; • Revise paraphernalia laws to decriminalize syringe possession; • Increase the availability of drug treatment and overdose prevention, including Medication-Assisted

Treatment and naloxone training and distribution; • Ensure education of law enforcement, criminal justice personnel, health department staff, healthcare

providers, pharmacists, and other relevant professional and community partners regarding the benefit of syringe services programs, as well as other harm reduction strategies, and relevant laws, policies, and processes; and

• Assure adequate resources to support health department surveillance, program planning, and program evaluation capacity to assess disease and risk behavior trends and the impact of syringe services programs, as well as other disease prevention and health promotion interventions for persons who inject drugs, on local health outcomes.

Furthermore, NACCHO urges Congress to remove the ban on the use of federal funds to support syringe services programs. Justification Injection drug use is a major route of transmission for HIV, viral hepatitis, and other blood-borne pathogens. Over the past 25 years, syringe services programs have proven to be highly effective at reducing HIV transmission among people who inject drugs and are an essential strategy to prevent hepatitis C virus (HCV) infection. In addition to providing sterile syringes and other injecting equipment, many syringe service programs also provide medical and social services, including HIV and viral hepatitis testing, overdose prevention training, referrals to social services and housing, and linkages to medical care, mental health care, and substance use treatment, to individuals who are not often served by traditional healthcare providers.1

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In the United States, HIV incidence among people who inject drugs declined by approximately 80% from 1988 to 2006 following the adoption of syringe service programs in a number of states.2 Despite that overall decline, people who inject drugs continue to represent a substantial proportion of persons with new HIV diagnoses, accounting for approximately 8% of new HIV infections in 2010 and 15% of those living with HIV in 2011.3 Since the epidemic began, approximately 186,728 people with AIDS who inject drugs have died.4 The sharing of drug injection paraphernalia is the primary risk factor for HCV infection. The rate of reported new hepatitis C infections has risen rapidly nationwide, more than doubling from 2010 to 2013.5 An estimated 3-4 million people in the United States are living with chronic hepatitis C, which is at least 10 times more infectious than HIV. In 2007, the number of U.S. deaths associated with hepatitis C surpassed those from HIV for the first time. After receiving reports of approximately 800-1,000 cases of acute hepatitis C each year from 2006-2010, there was a significant increase of 151.5% in reported cases of acute hepatitis C infection from 2010 to 2013. Based on surveillance data and epidemiologic studies, new cases of HCV are highest among young persons who are white, live in non-urban areas, and have a history of injection drug use.6 The number of cases reported represent only a fraction of the total number of new hepatitis C infections. Additional capacity for surveillance to detect these new infections and additional prevention capacity to link persons to services and medical care that can stop transmission are needed, particularly for states already reporting increases in transmission. A comprehensive public health response that includes expanded syringe access is necessary to reduce the transmission of HCV, HIV, and other blood-borne pathogens. Numerous federally funded studies, including studies conducted by the Centers for Disease Control and Prevention (CDC) and the Institute of Medicine (IOM), have established that syringe exchange is an effective HIV prevention intervention and does not promote drug use.7-10 Rather, studies show that people who inject drugs who participate in syringe services programs are more likely to enroll and complete substance use treatment. A study in Seattle found that new syringe services program participants are five times more likely to enter a drug treatment program than nonparticipants.11 Drug treatment programs, such as Medication-Assisted Treatment for opiate dependence, have been shown to substantially reduce the frequency of drug use, other risk behaviors, and new infections.12 In 2011, the U.S. Surgeon General determined that syringe services programs reduce both drug abuse and the risk of HIV infection.13 Syringe services programs may also provide the overdose reversal medication naloxone. Drug overdose is the leading cause of injury-related death in the United States, killing more people every year than auto accidents. Opioids (both prescription painkillers and heroin) are responsible for most of these deaths. The death rate from prescription opioid-caused overdose nearly quadrupled from 1999 to 2013, while deaths from heroin overdose rose 270% between 2010 and 2013.14Most opioid overdose deaths can be prevented by the timely administration of naloxone. In the event of an overdose, witnesses such as injecting partners, friends and family, and first responders (e.g., law enforcement, Emergency Medical Services) should be trained to administer naloxone and have access to this life-saving medication. Syringe services programs have unique access to people at risk of overdose prevention, making them important points of naloxone distribution and training. In the United States, public funding of syringe services programs has been limited due to a ban on the use of federal funding for syringe service programs, which was first enacted in 1988. In December 2009, the 111th Congress ended the nearly 20 year prohibition of using federal funds to support syringe service programs; however, in December 2011, the 112th Congress reinstated the ban through the Labor, Health and Human Services, and Education Appropriations bill included in the FY2012 Consolidated Appropriations Act (P.L.

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112-74). As long as the ban on federal funding to support syringe services programs is law, the responsibility of permitting, funding, and implementing such programs falls to the state and local level, which has resulted in a wide variation in syringe services program availability. Additional resources, as well as the removal of the ban on the use of federal funds to support syringe services programs, are needed to fully plan, implement, evaluate, and expand the inclusion of syringe services programs in comprehensive HIV and HCV prevention efforts and to address the health of people who inject drugs. The cost savings of infections averted by syringe services programs are significant. Lifetime treatment of an HIV-positive person is estimated to cost $326,500 on average, whereas a sterile syringe costs less than a dollar.15 An analysis conducted in 2015 calculated that the capacity of existing syringe services programs to provide a new syringe for each injection is estimated to be sufficient to meet only 3% of the need, and that expanding syringe services program coverage to meet even 10% of injections would avert nearly 500 new HIV infections annually.16 Additional savings will be incurred by preventing the transmission of HCV and other blood-borne diseases, as well as supporting the overall health and well-being of people who inject drugs through linkage to substance use treatment, preventive medicine, and other health and supportive services offered by syringe services programs. References 1. Centers for Disease Control and Prevention. (2012). Integrated prevention services for HIV infection, viral hepatitis, sexually

transmitted diseases, and tuberculosis for persons who use drugs illicitly: summary guidance from CDC and the U.S. Department of Health and Human Services. Morbidity and Mortality Weekly Report, 61(No. RR-5). Retrieved June 1, 2015, from http://www.cdc.gov/mmwr/preview/mmwrhtml/rr6105a1.htm

2. Centers for Disease Control and Prevention. (2015). HIV in the United States: At A Glance. Retrieved June 1, 2015, from http://www.cdc.gov/hiv/pdf/statistics_basics_ataglance_factsheet.pdf

3. Ibid. 4. Ibid. 5. Centers for Disease Control and Prevention. (2015). Increases in hepatitis C virus infection related to injection drug use among

persons aged ≤30 years — Kentucky, Tennessee, Virginia, and West Virginia, 2006–2012. Morbidity and Mortality Weekly Report, 64(17). Retrieved June 1, 2015, from http://www.cdc.gov/MMWr/preview/mmwrhtml/mm6417a2.htm

6. Centers for Disease Control and Prevention. Viral Hepatitis Surveillance, United States, 2013. (2013). Retrieved June 1, 2015, from http://www.cdc.gov/hepatitis/statistics/2013surveillance/index.htm

7. National Commission on Acquired Immune Deficiency Syndrome. (1991). The twin epidemics of substance use and HIV. Retrieved June 22, 2015, from http://harmreduction.org/wp-content/uploads/2012/01/NationalCommissiononAIDS1991

8. U.S. General Accounting Office. (1993). Needle exchange programs: research suggests promise as an AIDS prevention strategy. HRD-93-60. Retrieved June 25, 2015, from http://www.gao.gov/products/HRD-93-60

9. Office of Technology Assessment, Congress of the United States. (1995) The effectiveness of AIDS prevention efforts. Retrieved June 22, 2015, from http://ota.fas.org/reports/9556.pdf

10. National Research Council and Institute of Medicine. (1995). Preventing HIV transmission: the role of sterile needles and bleach. Retrieved June 22, 2015, from http://www.nap.edu/catalog/4975/preventing-hiv-transmission-the-role-of-sterile-needles-and- bleach

11. Hagan, H., McGough, J.P., Thiede, H., Hopkins, S., Duchin, J., & Alexander, E.R. (2000). Reduced injection frequency and increased entry and retention in drug treatment associated with needle-exchange participation in Seattle drug injectors. Journal of Substance Abuse Treatment, 19, 247–252.

12. Metzger, D.S., Woody, G.E., & O’Brien, C.P. (2010). Drug treatment as HIV prevention: a research update. Journal of Acquired Immune Deficiency Syndrome, 55(Suppl 1), S32-6.

13. Health and Human Services Department. (2011). Determination that a demonstration needle exchange program would be effective in reducing drug abuse and the risk of acquired immune deficiency syndrome infection among intravenous drug users (Federal Register Notice). Retrieved June 1, 2015, from https://www.federalregister.gov/articles/2011/02/23/2011- 3990/determination-that-a-demonstration-needle-exchange-program-would-be-effective-in-reducing-drug-abuse

14. Davis, C. (2015). Naloxone for community opioid overdose reversal. Public Health Law Research. Retrieved June 25, 2015, http://phlr.org/product/naloxone-community-opioid-overdose-reversal

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15. amfAR, The Foundation for AIDS Research. (2015). Preventing HIV and Hepatitis C Among People Who Inject Drugs: Public Funding for Syringe Services Programs Makes the Difference. Retrieved June 25, 2015, from http://www.amfar.org/uploadedFiles/_amfarorg/On_the_Hill/BIMC_SSP_IB-WEB-VERSION_041315.pdf

16. Nguyen, T.Q., Weir, B.W., Pinkerton, S.D., Des Jarlais, D.C., & Holtgrave, D. (2012, July). Increasing investment in syringe exchange is cost-saving HIV prevention: modeling hypothetical syringe coverage levels in the United States. Presented at the 19th International AIDS Conference, Washington, D.C.: Abstract no. MOAE0204. Retrieved June 25, 2015, from https://www.aids2014.org/Abstracts/A200746842.aspx

Record of Action Proposed by NACCHO HIV/STI Prevention Workgroup Approved by NACCHO Board of Directors December 11, 2005 Updated July 2010 Updated June 2015