Table 4

Summary of stress outcomes

Stress outcome (from one RCT)OPK groupControl groupMean difference95% CI# effect sizesStudy designTotal np value
PSS17.766.483715.786.25401.98−0.91 to 4.871RCT770.18
PANAS: positive affect29.7510.243634.268.0638−4.51−8.77 to −0.251RCT740.04
PANAS: negative affect17.556.973816.906.64400.65−2.42 to 3.721RCT780.67
SF-12: physical attributes41.864.003841.123.14400.74−0.88 to 2.361RCT780.37
SF-12: mental attributes46.407.153846.155.11400.25−2.54 to 3.041RCT780.86
Cortisol:creatinine ratio139.3059.0337156.2389.4438−16.90−51.87 to 18.071RCT750.34
E3G:creatinine ratio101.5952.343795.2452.43386.35−17.76 to 30.461RCT750.60
  • SF-12: Short-Form-12 Health Survey. It is a short, reliable, validated generic questionnaire for functional health status and outcomes, with both physical and mental health composite scores. Higher scores indicate higher health-related quality of life (range 0–100).

  • E3G:creatinine ratio: ratio of estrone-3-glucuronide (ng/mL) to creatinine (g/dL). E3G is an oestrogen marker associated with depression and anxiety, where a higher ratio indicates higher depression/anxiety.

  • PANAS: The Positive and Negative Affect Schedule (PANAS) comprises 10 positive affects (interested, excited, strong, enthusiastic, proud, alert, inspired, determined, attentive, active) and 10 negative affects (distressed, upset, guilty, scared, hostile, irritable, ashamed, nervous, jittery, afraid), where higher scores indicate stronger emotion (range 10–50).

  • Higher scores indicate higher stress, based on perceptions of how unpredictable, uncontrollable and overloaded participants find their lives (range 0–40).

  • OPK, ovulation predictor kit; PSS, perceived stress scale; RCT, randomised controlled trial; n, sample size.