Collecting Sexual Be.. - TREE

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Collecting Sexual Be.. - TREE

Pamina M. Gorbach, MHS, DrPH

Professor

Epidemiology & Infectious Diseases

University of California, Los Angeles


Inherent Challenges

Research participants CAN’T provide

accurate data

Research participants WON’T provide

accurate data


What Exists: Sources for Sexual

Behavior Data

Large representative household surveys of

sexual behavior

Surveys of STD and family planning clinic

patients

Surveys of “high risk” populations – CSW,

MSM, street youth, drug users


Health Behavior Surveillance:

International

Demographic Health Surveys

Behavioral Surveillance Surveys


Other Sources Of Data: Clinical

Trials on HIV Prevention

From NIH funded networks : HPTN, HVTN,

MTN, ACTG, IMPACT (PACTG)

Usually multi-country with standardized

measures

Within US muti-city (ie EXPLORE, Brothers,

ISIS)


Relevant Topics Covered in

Surveys

Frequency of sexual behavior by act

HIV prevention methods used by act

Sexual acts practiced by partner type

STDs (reported, test results or clinic records)

HIV status


Indiana: National Survey of

Sexual Health and Behavior

Journal of Sexual Medicine - http://www.nationalsexstudy.indiana.edu/


Journal of Sexual Medicine - http://www.nationalsexstudy.indiana.edu/

Sexual Behavior: NSSHB 2010 –

n=2,813 women; n=2,857 men


Journal of Sexual Medicine - http://www.nationalsexstudy.indiana.edu/


Chandra A, Mosher WD et al. Sexual Behavior, Sexual Attraction, and Sexual Identity in the

United States: Data From the 2006–2008 National Survey of Family Growth. National Health

Statistics Reports n Number 36 n March 3, 2011


Chandra A, Mosher WD et al. Sexual Behavior, Sexual Attraction, and Sexual Identity in the

United States: Data From the 2006–2008 National Survey of Family Growth. National Health

Statistics Reports n Number 36 n March 3, 2011


Sex Measures: US Surveys

Measure/Survey Name NSFG NHANES GSS NHBS NSSHB

Age of first sex X X X

Lifetime # partner X X* a

Past year # partners (by

gender)

X X* X X*

Past year # of times sex X X*b

Past month # times sex X X Xb

Condom use last sex X X X Xb

•Separates by Oral sex

•a- # of partners last 5 years, # of partners since age 18

•B – presented in categories: not in past year, few times per yr-weekly, few times

per month-monthly, 2-3 x per week, >=4 times per week


Data not Perfect: NHANES

Males - “In the past 12 months, with how

many males have you had anal or oral sex?

and “With how many of these males have

you had only oral sex? ”

Females: “In the past 12 months, about how

many times have you had vaginal or anal

sex?”

“In the past 12 months, about how often

have you had vaginal or anal sex without


NHBS

38. Have you ever had oral or anal sex

with a man?

39. How old were you the first time you

had oral or anal sex with a man?

40. In the past 12 months, with how

many different men have you had oral or

anal sex?


What data is needed?

Transmission Dynamics Model

R 0 = ß x c x D

R 0 = Case reproduction rate

ß = Efficiency of transmission

C = Mean rate of partner change

D = Duration of infectiousness

Higher the value of R 0 , greater spread of infection


Issues in Questionnaire Design


Respondent Tasks

Interpret –

• etic vs emic: respondent and questioner may have

different understandings of the question’s meaning

Retrieve Memories

• Episodically – discrete, detailed, specific, or uniqu

events

• Semanticaly, - schemas or generalizations

○ classes of events with little or no detail about specific episodes


○ Frequent, routine, or regularly recurring events are more likely

to be reported as schemas than are unique, unusual,

remarkable events


Respondent Tasks (2)

Form a judgment – a perceived risk? Did the

risk exist?

• Rating, estimating frequency of the event, agreeing

or disagreeing with a particular position, or

evaluating the relative importance of conflicting

information retrieved from memory in order to form a

judgment.

Edit response – social desirability of question

• Socially desirable behaviors frequently overreported,

whereas undesirable behaviors may be

underreported. Varies by gender, age, culture…


Typical Problems w/ Questions

Over demanding recall:

How many times did you go on a date with

your spouse before you were married?

Computational problems:

How many times did you have sex in your

lifetime?

Examples in questions:

What forms of HIV protection, such as

condoms, have you used in the past month?


Typical Problems: Asking Questions

Leading questions:

Don’t you see some danger in

having sex without condoms?

Loaded Questions:

Do you advocate condom use for HIV

prevention to save human lives?


Temporal problems

(1) Time in relation to time periods

‘in the last year’,

Can have a number of meanings including the

‘last calendar year’ or ‘the last 12 months’

(2) Time spent on activities.

all of the time’ and ‘some of the time’.

May leave respondents confused about selecting

an appropriate option when in fact a precise

option may be more suitable.


Question wording and order

• Did you use a condom the last time you had sex?

versus

• Were you able to use a condom the last time you had

sex?

Beginning with non-use rather than use:

“In how many sex acts did you not use a condom?”


Sources of Response Bias

1. Social Desirability

2. Yea and nay-saying

3. Prestige

4. Threat

5. Hostility; Mental State; Question order; Nonresponse;

Fatigue – burden; Timing in study


Types of Sexual Risk Questions

Two major categories of sexual risk measures:

Count data: Measures of discrete events on a

ratio scale. Ask participants to report the exact

number of times they engaged in a sexual risk

behavior during a specified period of time.

Relative frequency measures - Assess

unprotected intercourse relative to the total

number of intercourse occasions


Count Data

“How many times did you have vaginal sex during

the past three months” and

“How many of these times did you use a condom?”

Can be collected by direct question or Timeline

Followback (TLFB) methods, which assess

sexual risk behavior on event level.

Each single event is recorded as either protected

or unprotected, and count measures are derived

by summing all occasions of unprotected

intercourse that a person reports. Latter 2 time

consuming to collect.


Relative Frequency (1)

1. Proportions or percentages: derived from count

data but are ratios of protected or unprotected

intercourse to the total # of intercourse

occasions. Calculated by individual.

2. Percentage ratings: Rating the use of condoms

on a percentage scale.

“How often did you use condoms when you had sex in the

past three months?” Response is 11-point scale

ranging from 0 to 100 percent in ten percent

increments.

Estimates only and provides ordinal data in form of

ordered categories.


Relative Frequency (2)

3. Categorical measures: i.e. relative condom use. Likert

scales. Asks participants to report the frequency of

condom use relative to the frequency of intercourse. Such

as: using condoms “every time,” “sometimes,” or “never.”

3. Dichotomous measures: Two categories. Asks about

consistent condom use (“always”) versus inconsistent

(“not always”). Can also be derived from ordinal data or

count measures. Measures of relative condom use -

provide information only about condom use relative to the

total number of intercourse occasions.

Remember washes out context of risk (a) have used

condoms all but one time, (b)never use condoms because

in a mutually monogamous relationship, and (c) engage in

trade sex with multiple partners without using condoms.


Count or Relative Freq?

Yield different information

Most correlational studies in a review use relative

frequency –(epidemiology or descriptive)

Count data more often in intervention & methodological

studies

Remember: the likelihood of becoming infected with

STI/HIV is proportional to the number of times exposed

if control for factors such as the partner’s level of risk,

infectiousness of partner, index’s biological

vulnerability (ie existing STI), ect


Count wins!

Count data provide a more precise

indicator of STI/HIV acquisition risk (and

risk reduction)

Count data more versatile because they

can be transformed into proportions and

categorical data if needed. Can yield

both absolute and relative frequency

measures.


Interpretation of Reported

Frequency

Relative frequencies are not simple

translations of absolute frequencies; they

incorporate potentially useful evaluative

information

Woody Allen’s Annie Hall:

‘Both Annie and Alvie Singer report that they

have sex three times a week, but she

characterizes this as ‘‘constantly,’’ whereas his

description is ‘‘hardly ever’’ (Schaeffer and

Presser 2003, p. 74).

(Schaeffer and Presser 2003, p. 74).


Are they telling the truth?


Validating Questions: Cognitive

interviews

“Cognitive labs” at U.S. survey research centers,

e.g., Census Bureau, NCHS, BLS, RTI

Examine survey response process

Identify problematic questions

Examine how respondents answer questions

Methods:

• Think aloud interview – discuss process after

interview

• Verbal probing – probes after question answered

Behavior coding – # of times respondent: asked

for clarification, answered without probing, reasked

because response inconsistent


Consider Mode of Interviewing

Face-to-face interviews (FTFI)

Paper diaries

Electronic diaries

Audio Computer-Assisted Self-Interviewing (ACASI )

Voting Boxes

Interactive Voice Response Survey (IVRS) & SMS

Smart phone Apps

Electronic Events Monitoring Systems

(Wisebag; Wisepill; MEMS)


FTFI vs. ACASI*(%)

OR (95%CI)

Zimbabwe 100% condom 42.8 - 47.7 1.1 (0.9-1.4)

hormonal method 67.5 - 53.3 0.6 (0.5-0.6)

withdrawal 1.2 - 3.4 2.7 (1.5-4.7)

rhythm method 0.5 - 8.9 17.8 (7.4-42.9)

multiple partners 0.4 - 2.4 5.7 (2.1-15.2)

Kenya 5 ever had sex 48.3 - 42.8 1.22

sex with stranger 3.7 - 13.9 3.45**

ever forced sex 6 - 15.8 2.73**

Kenya 9 multiple partners 20.7 - 34.9 2.35**

sex with stranger 3.7 - 14.2 4.25**

ever forced sex 12.9 - 31.3 3.35**

Brazil 14 sex - 6 months 91.8 - 90.2 0.79 (0.47-1.35)

MSM behavior 5.7 - 12.6 2.52 (1.38-4.61)

India 10 vaginal intercourse 35 - 11 0.23**

anal intercourse 4.3 - 15 3.87**


# p=0.06

*p


How Does Reports in

Questionnaire Compare with

Biomarkers of Sex?

Sexual Behavior Reports

Brazil (Hewett, Mensch

et al., 2008)

Zimbabwe (Minnis et al.,

2009)

South Africa (Mensch et

al., 2011)

Biomarker ACASI FTFI

STI

X

PSA No diff No diff

RSID,

applicator

stain

X= significant association with biomarker

X


Is ACASI Better?

Increased reporting of some

sensitive behaviors –but not

adherence to HIV prevention

methods or treatment

Enables detection of very low

frequency behaviors (ie women’s

report of AI, drug use)

May be preferred by respondents

Requires investment in technology

and testing


Many Areas within “Behavioral”

Research on STIs/HIV

Behaviors

• Sex details: mechanical, social, logistical

• Hygiene practices & products & timing (before/after) - douching

• Lubrication usage (types, timing, repetition)

Partnership

• Dynamics: communication, sexual initiation

• practices by partner type

• Partner’s risks and exposures

Genital health

– Disease status (STI)

• Perceptions, awareness & experience symptoms

• Health care seeking and use

By: gender, partner type, location of sex, HIV status & orifice.


Conclusions:

Collecting Sexual Behavioral Data

Use validated measures – from existing studies

Examine existing data sources - rich but often miss

specific risk populations or detailed data

Consider respondents’ process to answer questions – too

burdensome? General? Unclear?

Conduct preliminary research (qualitative) to develop

questions – cognitive interviewing

Consider mode of interview (ACASI? SMS?) and

integration of biomarker or other data source – EM?)

Pre-test and pilot questionnaires

Take a class on questionnaire development!

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