Effectiveness of the CREIGHTON MODEL System to Avoid

Effectiveness of the CREIGHTON MODEL System to Avoid and to Achieve Pregnancy Joseph B. Stanford, MD, MSPH, CNFPMC Associate Professor Family and Preventive Medicine University of Utah School of Medicine

Why study use to avoid and achieve? • Couples who use Cr. M throughout their life will use it both ways. • In any Cr. M program, users will come for both reasons. • Interest in NFP to achieve is higher than interest to avoid (in USA). – About 33% interested to avoid; 25% to achieve – Missouri and Utah

• What is the effectiveness of Cr. M to avoid pregnancy? • What is the effectiveness of Cr. M to achieve pregnancy? • How do you distinguish between use to avoid and use to achieve? • What are the needs for future research?

Distinguishing between use to avoid and use to conceive • Unplanned and planned pregnancy • Achieving-related pregnancy

Pregnancy from genital contact during known fertile time • (Un)planned pregnancy • Fertility control • Responsibility for pregnancy belongs to the method. • Subjective, superficially measured. • Achieving-related pregnancy • Fertility cooperation • Responsibility for pregnancy belongs to the couple. • Objective, based on knowledge and behavior.

Pregnancy from genital contact during known fertile time • (Un)planned pregnancy • Sex and fertility are fantasized to be completely separate phenomena. • “Unplanned” is usually considered to be a negative outcome. • Achieving-related pregnancy • Sex and fertility are naturally and inseparably related. • Achieving-related pregnancy is almost always considered to be a positive outcome.

Consider 2 family planning methods • Inserted by doctor. • Suppresses fertility. • Has to be removed by doctor. • Encourages couple to forget about their fertility. • Low method pregnancy rate. • Low total pregnancy rate. • “Planned” Parenthood • Used by couple. • Cooperates with fertility. • Couple is continually encouraged to consider the gift and possibility of fertility. • Low method pregnancy rate. • Higher total pregnancy rate. • Responsible Parenthood

Distinguishing between use to avoid and use to achieve (Cr. M) • Use to avoid is avoidance of genital contact during known times of fertility. – Avoiding-related pregnancy • Use to achieve is any genital contact during known times of fertility. – Achieving-related pregnancy • Couples rarely have any difficulty grasping and accepting this approach.

• What is the effectiveness of Cr. M to avoid pregnancy? • What is the effectiveness of Cr. M to achieve pregnancy? • How do you distinguish between use to avoid and use to achieve? • What are the needs for future research?

Avoiding-related pregnancy rates • During use to avoid, method-consistent – method-related pregnancy rate – if method always used perfectly to avoid pregnancy • During use to avoid, method-inconsistent – use-related pregnancy rate – as method is used in “real life” • includes errors by user and/or teacher • Either of these can be calculated with fulldenominator or specific denominator. – Illustrate with method-consistent use

Method (perfect use) pregnancy rates during use to avoid 2 1 1 2 a b 1= cycles of method-consistent use; a= perfect use pregnancy 2= cycles of “real life” use with errors; b= pregnancy due to error Perfect use = a / [1+2] {full denominator; traditional measure} Perfect use = a / [1] {specific denominator; new measure}

Statistical approaches • Pearl rates – Influenced by length of follow-up (more=lower) • Net life table (multiple decrement) – Influenced by rate of discontinuation • Gross life table (single decrement) – Independent of rate of discontinuation – Higher rates than net life table • Kaplan-Meier (similar to life table) • Cox Proportional Hazards Regression – Multivariate modeling

Method (perfect) use pregnancy rates during use to avoid Selected Cr. M studies, full denominator, 12 -month Location Year Couplemonths NET Pregnancy Rate per 100 GROSS Pregnancy Rate per 100 Wichita 1985 2471 0. 6 1. 0 Houston 1989 5731 0. 2 USA, 5 sites 1998 14, 225 0. 7

Avoiding use pregnancy rates Selected Cr. M studies, full denominator, 12 -month Location Year Couplemonths NET Pregnancy Rate per 100 GROSS Pregnancy Rate per 100 Wichita 1985 2471 2. 1 3. 3 Houston 1989, 1999 5731 2. 8 3. 9 USA, 5 sites 1998 14, 225 3. 2 4. 7

Cr. M Effectiveness • Important Factors • Standardized method • Personalized instruction • Competent, trained teachers • Motivation • Couple communication • • • Not Important Regular cycles Educational status Socioeconomic status Religious denomination

• What is the effectiveness of Cr. M to avoid pregnancy? • What is the effectiveness of Cr. M to achieve pregnancy? • How do you distinguish between use to avoid and use to achieve? • What are the needs for future research?

Effectiveness to achieve pregnancy 1. The achieving related pregnancy rate is a demographic measure of consciously chosen fertility in the population over all cycles of use (full denominator) May include many cycles used to avoid 2. Normal fertility, pregnancy rate in cycles used to achieve (specific denominator) Includes only cycles used to achieve 3. Infertility, pregnancy rate (specific denominator) Essentially includes only cycles used to achieve With or without Natural Procreative Technology

Selected studies of Cr. M to achieve Cr. M Study Denominator Couples Pregnancy Comments Rate per 100 Metaanalysis, 1998 Full- all study cycles/months 1876 21. 0 net Normal fertility 28. 2 gross Many couples in study never tried to achieve pregnancy Fertilityfocused intercourse study Specific- only cycles to achieve 50 76 in first cycle; 100% at 7 cycles Irish Medical NPT Study Specific- only cycles to achieve 1239 46. 3 up to Infertility 24 months Mean age 36 years 29% previously failed IVF Normal fertility Excluded couples not conceiving (retrospective)

Effectiveness in infertility, method issues • Per cycle success rates are not appropriate for Cr. M (or any infertility treatment). – Biased measures used extensively for IVF and related techniques. • Cohort-based measures are appropriate for Cr. M, and to compare Cr. M to other infertility treatments. • Crude rates will underestimate effectiveness. • Traditional life tables will overestimate effectiveness (but probably less for Cr. M than for IVF).

Cr. M: effectiveness summary • With exact use to avoid pregnancy, yearly pregnancy rates are less than 1 per 100. • Accounting for user or teacher error, the yearly avoiding pregnancy rates are 2 to 5 per 100. – Effective teaching required. – Cr. M can be used in all reproductive situations to avoid. • Irregular cycles, discontinuing oral contraceptives, breastfeeding • (Most clearly shown in Creighton Model Texas study, 1999)

Cr. M: effectiveness summary • Nearly all pregnancies among Cr. M users result from intercourse during known fertile days. – The total pregnancy rate in Cr. M studies ranges from 17 to 33 at one year (per 100, Net). – The achieving-related pregnancy rate ranges from 14 to 30 at one year (per 100, Net). – Achieving-related pregnancy varies by external circumstances (ie, unemployment rates)

Cr. M: effectiveness summary • Cr. M is the method of choice for seeking pregnancy in infertility. – Depending on underlying age and diagnoseis, pregnancy rates without NPT may be around 33% – With Natural Procreative Technology, pregnancy rates will be 40 -80% or even higher, depending on underlying age and diagnosis.

• What is the effectiveness of Cr. M to avoid pregnancy? • What is the effectiveness of Cr. M to achieve pregnancy? • How do you distinguish between use to avoid and use to achieve? • What are the needs for future research?

Evaluating Cr. M Effectiveness • We need new Cr. M studies with the “specific denominator” approach for both avoiding and achieving pregnancy. • We especially need studies in – Breastfeeding women (avoiding) – Premenopause (avoiding) – Normal fertility (prospective, achieving) – Women using yellow stamps (postpeak and prepeak) – Different subtypes of infertility with medical or medical+surgical NPT • We need thorough, sound studies of the dynamics of achieving-related use.