Agreement Between the 2- and 3-Step Methods for Identifying Subtle Menstrual Disturbances.

Area of Science:

• Reproductive endocrinology
• Sports medicine
• Gynecology

Background:

• Subtle menstrual disturbances (SMDs) require accurate identification.
• The 3-step method (calendar, urine ovulation tests, serum sampling) is recommended but demanding.
• A less intensive 2-step method (calendar, urine ovulation tests) is a potential alternative.

Purpose of the Study:

• To evaluate the agreement between the 2-step and 3-step methods for detecting SMDs.
• To determine the reliability of the 2-step method as a substitute for the 3-step method.

Main Methods:

• Assessed 98 menstrual cycles (MCs) in 59 athletes using both 2-step and 3-step methods.
• Defined SMDs based on luteal phase length, progesterone levels, and ovulation status.
• Employed McNemar test and Cohen kappa (κ) for method agreement analysis.

Main Results:

• Substantial agreement (κ = .72) was found between the 2-step and 3-step methods.
• The 2-step method exhibited systematic bias, underdetecting 38.9% of SMDs.
• The 2-step method correctly identified 100% of non-SMD cycles but only 61.1% of SMD cycles.

Conclusions:

• Menstrual cycles identified as disturbed by the 2-step method are likely valid SMDs.
• The 2-step method's underdetection means it cannot definitively confirm the absence of SMDs.
• Clinical interpretation of the 2-step method requires awareness of its limitations in detecting all SMDs.