Table 4.

Summary of stress outcomes

Stress outcome (from one RCT)	OPK group			Control group			Mean difference	95% CI	# effect sizes	Study design	Total n	p value
	Mean	SD	n	Mean	SD	n
PSS	17.76	6.48	37	15.78	6.25	40	1.98	−0.91 to 4.87	1	RCT	77	0.18
PANAS: positive affect	29.75	10.24	36	34.26	8.06	38	−4.51	−8.77 to −0.25	1	RCT	74	0.04
PANAS: negative affect	17.55	6.97	38	16.90	6.64	40	0.65	−2.42 to 3.72	1	RCT	78	0.67
SF-12: physical attributes	41.86	4.00	38	41.12	3.14	40	0.74	−0.88 to 2.36	1	RCT	78	0.37
SF-12: mental attributes	46.40	7.15	38	46.15	5.11	40	0.25	−2.54 to 3.04	1	RCT	78	0.86
Cortisol:creatinine ratio	139.30	59.03	37	156.23	89.44	38	−16.90	−51.87 to 18.07	1	RCT	75	0.34
E3G:creatinine ratio	101.59	52.34	37	95.24	52.43	38	6.35	−17.76 to 30.46	1	RCT	75	0.60

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.