NFP services and methods in Australia: a survey evaluation.

The results of an analysis of 1139 cases or couples using a natural method of family planning to avoid contraception are presented. The cases provided 1218 episodes of use. Results are reviewed according to the following: results by method--Pearl formula analysis (method groups by standard unplanned pregnancy rate method groups by refined unplanned pregnancy rate life table analysis and births averted); results--theoretical use effectiveness (service failures); results by client group (achievement of pregnancy group and correspondence groups); analysis of factors and variables associated with the use effectiveness of natural methods of family planning and method and use effectiveness. The use episodes cover 16987 cycles of prospective use. Mixed method practitioners provided 165 use episodes covering 2620 prospective cycles. The standard unplanned pregnancy criteria yielded a total of 308 unplanned pregnancies. On a comparative basis sympto-thermal methodologies appeared to be for this sample surveyed in Australia more use effective than the other natural method surveyed. This generalization appears to hold regardless of whether the standard or refined pregnancy rates were used and no matter what technique of use effective evaluation was employed. Of the 2 major variants of the sympto-thermal methodology variant A--that which relies upon a strict application of the rhythm rule to the preovulatory phase of the cycle--appeared more use effective than variant B--which places more emphasis upon the mucus symptom. This trend was consistent regardless of whether the standard or refined pregnancy rates were used and no matter what technique of use effective evaluation was employed. The life table analysis of mixed method use effectiveness apart the least effective method surveyed appeared to be the ovulation method. In all instances and regardless of the type of pregnancy rate or type of use effectiveness evaluation employed the ovulation method appeared to be consistently a less effective natural family planning method. When unplanned pregnancies were distributed by method and type of unplanned pregnancy (methodological/behavioral) 2 patterns were evident. Sympto-thermal variant A (with a rhythm rule) yielded results which were uniformly superior to variant B (mucus rule). Variant A had a methodological failure rate of approximately 2 pregnancies/100 woman years; variant B had nearly twice that rate.