Principal Investigators: Anthony P.Macmillan Coxon, PhD
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Transcript of Principal Investigators: Anthony P.Macmillan Coxon, PhD
January 2004 Sociology, University of Edinburgh
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Project SIGMA
Principal Investigators:Anthony P.Macmillan Coxon, PhD
Hon. Professorial Fellow, Graduate School of SPS, University of Edinburgh
Thomas J. McManus, FRCOGConsultant, Royal London Hospital
Project SIGMA, Edinburgh and Sigma Research (London) together constitute
PROJECT SIGMA
Researching and Serving the Gay and Bisexual Community for 18 years
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What’s
UNIQUE
about……. Sexual Diaries?
byProfessor Tony Macmillan CoxonSSPS, University of Edinburgh, Project Sigma
PARTICULARSPECIAL
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DIARIES
Only good girls keep diaries. Bad girls don’t have the time.
Tallulah Bankhead (1903 – 1968) US Actress
What is a diary as a rule? A document useful to the person who keeps it, dull to the contemporary who reads it, invaluable to the student, centuries afterwards, who treasures it!
Ellen Terry (1847–1928) British actress,The Story of
My Life, Ch. 14
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I never travel without my diary. One should always have something sensational to read in the train Oscar Wilde (1895) The Importance of Being
Earnest
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0: BACKGROUND From earliest SIGMA pre-tests in 1982, estimates and self-
reports of frequency of sexual behaviours were shown to be [1988b]:
unreliable (test-retest;repeat questions in interview)
retrospection- biased
detail and accuracy of reports dependent (inversely) on elapse time
1-week retrospective “work-back from today” showed even 3-day lapse distorted detail and only gross properties survived
“chunked” (suspicious rounding of numbers and “grossing up”
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... This led to basic re-thinking & development:
development of a schema/model of “structure of sexual behaviour” [1992] (which determined both form of Sexual Behaviour Inventory used in
interview schedule AND format for sexual diary method)
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method of sexual diaries (Self-administered; month-long) to make possible ....
reliable, valid, accurate measurement of
detailed sexual behaviour and sequences of behaviour
in a contextual and relational setting.
Reduce retrospection bias; S.D.s are a non (interviewer)-reactive method (cf interpretation of “the condom broke”)
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COLLECT / elicit (sexual diaries) (Qualitative) Transcribe
ENCODE Tag
SELECT
ANALYSE (Integrate) Analyze(SDA Programs) (Atlas/ti &c)
HOW? Sequence of Using Sexual Diary Methodology
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Abbreviated example of a one-week of a sexual diary
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ANALYSIS
By means of a SCHEMASCHEMA common to Project SIGMA Sexual Inventory and Sexual Diaries [JSR 1992]
• The Schema has linguistic analogies:
Sexual Session = SentenceSentenceSexual Act = WordWordSexual Behaviour = Word-stemWord-stem
• Schema puts eliciting format and encoding structure for sexual scripts into 1:1 correspondence
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SIGMA schema of sexual behaviour
(relevant to sexual transmission of HIV)
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The SCHEMASCHEMA has a well-defined grammar
…..usually shielded from the enquirers’ eyes…
Formal Grammar of Revised Sexual Diary Code
<session> ::= <act> <act> ' ' < session>
<act> ::= '(' <act> ')' '/' <accomps> <act> '/' <accomps> <partner_label> <session> <act> '&' <act> <modality> <behaviour> <modality> <behaviour> ',' <outcomes>…………/cont.
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OUTCOME (risk order)Code Destination
N No ejaculation
X Ejaculation `elsewhere'
I On Me (ie: on EGO)
O On Him (ie: on ALTER)
C into a Condom
H In Him (ie: in ALTER)
M In Me (ie: in EGO)
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PROGRAMNAME
FULL NAME & DESCRIPTION SDA(pp)
BAPN Both-Active-Passive-Neither: Modality (Sexual Role) Analysis by sexual act
5,35
COLLECT
Sexual Session length distribution and Mean length
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CONDOM Percentage of sessions in which a condom was used
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COOCUR Co-occurrence of sexual acts in a session. (Different definitions of co-occurrence: act-specific and session specific)
7-8;37
CPSANAL
Co-occurrence (similarity, symmetric), Precedence (asymmetric: how often a precedes b); Successor (asymmetric: how often a succeeds b). Output matrix to Scaling and Clustering programs.
7-8;39
EVER Prevalence (How often a sexual act has ever been done)
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FREQACT Frequency of (sexual) act by modality 40-41
GINI / LORENZ
Frequency (and cumulative) frequency of Individuals who do exactly n acts and of Acts (basis for Lorenz distribution, qv) and Gini Coefficient
Suppl.
KWIC Key-word-in-context: Instances of specified modality/act in context of session, centred and referenced
43
MARKER Analysis of sexual acts that start and end sessions, and of the “destination” of the ejaculate/s, if it/they occur
44-5
MEDPOL Median Polish Tukey Means analysis of 2-way table, defined by SIGMA types
Suppl.
RISK Frequency of type and destination of outcome (ejaculation) by sexual act ( Anal Intercourse, Fellatio or Masturbation; denominator can be N Acts or N Individuals
8, 45-46
SESSTYPE
Session-Type: typology of sessions in terms of: Solo-Quick(1-act) - Role (preponderance of Active or Passive role) - Reciprocated - Other
9, 47
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WHAT FOR? Applications
Primarily...
Counts of incidence and prevalence of sexual practices & variants, on both {Individual/month} and {Acts/month} bases
In contextual / sequential / vocational environment
Within/Across subgroups (HIV+, condom usage, age, relationship-type ...)
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For example: Role-separation (“gendering” ( [1993]) Concentration of potential and actual risk
behaviour[1999] Inferring the contextual “rules” of risk [1994b, 1995b] Factors influencing risk behaviour (e.g. substance use;
alcohol) [1994a] Partner-specific sexual behaviour [1988] Differential: location/arenas – home; club; saunas,
Public Sex Environments (cottaging, tea-room) [1996] times – weekends, holidays, at parents
Different subgroups: SM/Leather [1996], Minority Ethnic groups; Young gay men
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BRIEF EXAMPLE ... Concentration
• Example which combines Individual with Acts data derived from diaries.
• Concentration is akin to Property/Income distribution: What Percent of Individuals “own” what Percent of Risk Activity?
• Inter-relating two distributions cumulatively
• Useful Equality baseline ... where n% of individuals own n% of risk activity ... allows us to see how far actual concentration departs from equal shares ... Gini Coefficient.
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BRIEF EXAMPLE ... Concentration/cont.
• This needs two cumulative distributions
• ... cross-related to each other
• to produce Lorenz diagram and
• measure of departure from “equal shares”
• and then go on to examine characteristics of the distribution and who the “risk-rich” are
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(i) No of acts of anal inter-course (to ejaculation)
per/month
(ii)N of men (diary/m)
(Iii)Percent of men
(iv)Cumulative % of men
(v) N of acts ofanal in-tercourse
(vi)Percentof acts
(vii)Cumulative % acts
1 244 38.9 38.9% 244 9.8% 9.8%
2 136 21.7 60.5 272 11.0 20.8
3 62 9.9 70.4 186 7.5 28.3
4 49 7.8 78.2 196 7.9 36.2
5 34 5.4 83.6 170 6.9 43.1
6 20 3.2 86.8 120 4.8 47.9
7 11 1.8 88.5 77 3.1 51.0
8 13 2.1 90.6 104 4.2 55.2
9 7 1.1 91.7 63 2.5 57.7
10-19 36 5.7 97.5 466 18.8 76.5
20-49 14 2.2 99.7 405 16.3 92.8
50-104 2 (=628)
0.3 100.0 178=2481
7.2 100.0
Distributions of acts of anal intercourse to ejaculation (AIE) per month
Mean = 3.8, Md = 2 acts of AI/month. IQR = 3
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% of Total Acts of AI per month
(SIGMA diary data)
No. of acts of AI/month
Pe
rc
en
ta
ge
0
10
20
30
40
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80
Percentage of acts of AI accounted for by those who do exactly x acts a month
Constituent Distributions of anal intercourse
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% of Individuals who have exactly X acts of AI/month
(SIGMA diary data)
No. of acts of AI/month
Percen
tag
e
0
5
10
15
20
25
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40
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80
Percentage of individuals who do exactly x acts of AI a month
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Lorenz curve of all acts of Anal Intercourse/month
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TYPE OF AIE[1]
UNPROTECTED WITH CONDOM
SummaryCharacteristics:
ACTIVE
PASSIVE
ACTIVE
PASSIVE
NUMBERS INVOLVED:No. of fuck-acts/month No. of individuals
434
188
442
154
362
163
380
172
SUMMARY INFO:Average no. acts/month Dispersion (IQR)
2.31, Md=1 1
2.87, Md=1 2
2.22, Md=1 1
2.21, Md=1 1
LOW-END CONCENTRATION:% of individuals who do exactly 1 act/month% who do 1 or 2 acts/month
54%
75%
51%
73%
55%
75%
60%
75%HIGH-END CONC.Top 1/10th individuals account for: (%acts)
34%
46%
32%
34%OVERALL CONCENTRATION: (Gini)
0.42
0.51
0.42
0.43
Characteristics of four types of AIE
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Use & Development of Sexual Diaries in Project SIGMA
Largest
Most extensive (in time, location, age, etc)
Well-documented data set of sexual diaries
With associated special-purpose software
Enabling session-based, act-based or individual-based analysis
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• 1,661 individuals from
• 25 sites in the UK produced
• 1,963 month-long diaries
consisting of
• 32,142 sexual sessions
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ARCHIVING : SEXUAL DIARY DATA……Exist in two forms:Natural-language (anonymised)
originals • hard-copy diaries have been anonymised,
indexed, documented and reduced to micro-fiche form;
• now archived and lodged in Wellcome Contemporary Medical Archives Centre, London;
• accessible to any bona fide researcher. • http://www.wellcome.ac.uk/en/library/homlib/
HOMlibCOLspeCMCaccGENmtr.html#P
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ARCHIVING : SEXUAL DIARY DATA……Machine-readable (flat) database of
diary records • SIGMA Panel members’ (and additional
groups’) diary data in pre-database format (.dmp files) for entry into other database and special purpose analytic software;
• To be lodged at Data Archive, Essex (http://dawww.essex.ac.uk/);
• Plans for dissemination of these data, and wider SIGMA data in NESSTAR environment:
• http://www.nesstar.org/
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ARCHIVING : SEXUAL DIARY DATA……Cross-linking index
• In preparation to enable original diary, machine readable version and interview data to be cross-accessed;
Special-purpose software• Written to store and analyse these
data (SDA: Sexual Diary Analysis) • These data & programs also available
from Data Archive / Project SIGMA Essex
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WEBSITE
Contains Documentation, Programs, Sample Data, Diary Form, Publications, Conference OHP’s:
http://www.sigmadiaries.com/
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CONCLUSIONS
Sexual Diaries….. At the humblest level, offer a markedly
different, non-reactive contrast to SAQ/interview data on sexual behaviour
data are more like a “trace” than an account; the significant data are “read-off” the sexual accounts, not estimated by the respondent
relate both acts and individuals and allow their integration ( e.g. concentration)
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CONCLUSIONSSexual Diaries…..
can be interpreted not only as scripts, but linguistically as a simple code (language) and as free text, thus making semantic and grammatical analysis possible ( e.g. KWIC, co-occurr)
allow development and definition of higher-level categories (risk; “oriented risk”, power session...)
allow definition of rules, patterns sequences of any complexity, which can be defined, retrieved, & tested
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WEBSITE
Contains Documentation, Programs, Sample Data, Diary Form, Publications, Conference OHP’s:
http://www.sigmadiaries.com/