Correction to: Metformin improved health-related quality of life in ethnic Chinese women with polycystic ovary syndrome.

The original article [1] contains a number of statements that the authors would like to be disregarded, noted ahead.

Correction

The original article [1] contains a number of statements that the authors would like to be disregarded, noted ahead:

In the Methods section, along with the references mentioned in the statement:

‘In order to account for the effect of medication behavior, the Morisky 8-item medication adherence scale (MMAS-8) [30] was applied to measure medication adherence. The MMAS-8 is one of the most commonly used self-report adherence questionnaires. The Chinese version of MMAS-8 has been validated among a convenience sample of 176 patients in China [31]. The scale showed acceptable internal consistency (Cronbach’s α = 0.77) and test-retest reliability (r = 0.88), and good construct validity.’

In the respective captions of Tables 3 and 4:

‘The analysis was adjusted for the effect of medication adherence via the Morisky 8-item medication adherence scale’.

These statements as well as the references contained within them are to be disregarded as it was discovered that the patients included in the analyses did not receive the MMAS and thus, the analyses did not adjust for the MMAS scores (as was erroneously asserted in the original text).

Table 3

Mixed effect model analysis of metformin effect on general HRQoL outcome measured via WHOQOL-Bref

WHOQOL-Bref	TotalCoefficient (SE)	Subgroups
		Normal weightCoefficient (SE)	OverweightCoefficient (SE)	Non- hyperandrogenismCoefficient (SE)	HyperandrogenismCoefficient (SE)
Total scores
Treatment time
Visit 2 (reference = visit 1)	−0.93 (1.04)	0.47 (0.77)	−1.72 (1.44)	1.49 (1.26)	0.79 (0.56)
Visit 3 (reference = visit 1)	0.06 (0.94)	0.07 (0.75)	−0.27 (1.45)	0.52 (1.30)	0.70 (0.56)
Physical domain
Treatment time	p = 0.010		p = 0.036		p = 0.015
Visit 2 (reference = visit 1)	0.58 (0.20)*	0.50 (0.29)	0.57 (0.28)*	0.62 (0.50)	0.55 (0.22)*
Visit 3 (reference = visit 1)	0.54 (0.20)*	0.50 (0.29)	0.64 (0.27)*	0.29 (0.51)	0.60 (0.22)*
Psychological domain
Treatment time
Visit 2 (reference = visit 1)	−0.90 (0.06)	−0.17 (0.34)	−1.49 (0.57)	0.63 (0.58)	−0.16 (0.23)
Visit 3 (reference = visit 1)	−0.06 (0.39)	−0.14 (0.33)	−0.76 (0.57)	0.17 (0.60)	0.002 (0.23)
Social domain
Treatment time
Visit 2 (reference = visit 1)	−0.61 (0.39)	0.10 (0.31)	0.18 (0.24)	−0.83 (0.69)	0.05 (0.21)
Visit 3 (reference = visit 1)	−0.31 (0.35)	−0.31 (0.30)	0.14 (0.25)	−0.02 (0.63)	−0.14 (0.21)
Environment domain
Treatment time
Visit 2 (reference = visit 1)	0.13 (0.15)	−0.07 (0.23)	0.29 (0.21)	−0.34 (0.27)	0.23 (0.18)
Visit 3 (reference = visit 1)	0.07 (0.16)	−0.06 (0.22)	0.17 (0.22)	−0.16 (0.28)	0.10 (0.18)

Note: Visit 1 is 1st office visit when patients were diagnosed with PCOS (baseline). Once PCOS was diagnosed, patients started metformin treatment. Visit 2 was 2nd office visit (1st-2nd month of treatment). Visit 3 was 3rd office visit (3rd- 4th month of treatment). The analysis was adjusted for the effect of medication adherence via the Morisky 8-item medication adherence scale

Abbreviations: HRQoL health-related quality of life, SE standard error

*p < 0.05

Table 4

Mixed effect model analysis of metformin effect on PCOS-specific HRQoL measured via Chi-PCOSQ

Chi-PCOSQ	TotalCoefficient (SE)	Subgroups
		Normal weightCoefficient (SE)	OverweightCoefficient (SE)	Non- hyperandrogenismCoefficient (SE)	HyperandrogenismCoefficient (SE)
Total scores
Treatment time
Visit 2 (reference = visit 1)	0.44 (0.56)	0.75 (0.86)	0.20 (0.75)	−0.58 (0.89)	0.61 (0.66)
Visit 3 (reference = visit 1)	1.25 (0.56)	1.77 (0.84)	0.80 (0.78)	0.11 (0.92)	1.45 (0.66)*
Weight domain
Treatment time
Visit 2 (reference = visit 1)	−0.06 (0.14)	0.11 (0.22)	−0.18 (0.19)	−0.04 (0.28)	−0.07 (0.17)
Visit 3 (reference = visit 1)	0.12 (0.15)	0.15 (0.21)	0.10 (0.20)	−0.01 (0.29)	0.15 (0.17)
Infertility domain
Treatment time	p = 0.043				p = 0.048
Visit 2 (reference = visit 1)	0.25 (0.18)	0.34 (0.23)	0.15 (0.29)	−0.06 (0.33)	0.32 (0.21)
Visit 3 (reference = visit 1)	0.46 (0.18)*	0.34 (0.24)	0.59 (0.28)*	0.12 (0.34)	0.52 (0.21)*
Menstrual domain
Treatment time
Visit 2 (reference = visit 1)	0.10 (0.18)	0.21 (0.29)	0.02 (0.24)	0.26 (0.39)	0.08 (0.20)
Visit 3 (reference = visit 1)	0.19 (0.18)	0.36 (0.27)	0.04 (0.25)	0.58 (0.41)	0.11 (0.20)
Emotions domain
Treatment time
Visit 2 (reference = visit 1)	0.07 (0.15)	0.15 (0.21)	0.01 (0.21)	0.82 (0.33)*	0.04 (0.18)
Visit 3 (reference = visit 1)	0.14 (0.15)	0.30 (0.21)	0.003 (0.21)	0.43 (0.29)	0.13 (0.18)
Body hair domain
Treatment time
Visit 2 (reference = visit 1)	0.03 (0.14)	0.18 (0.19)	−0.08 (0.20)	−0.34 (0.20)	0.10 (0.17)
Visit 3 (reference = visit 1)	0.02 (0.14)	0.24 (0.18)	−0.16 (0.21)	−0.37 (0.21)	0.10 (0.17)
Acne & Hair loss domain
Treatment time	p = 0.008		p = 0.043		p = 0.007
Visit 2 (reference = visit 1)	−0.51 (0.28)	−0.10 (0.19)	0.01 (0.20)	−0.46 (0.18)*	−0.55 (0.35)
Visit 3 (reference = visit 1)	0.45 (0.26)	0.08 (0.19)	0.33 (0.21)	−0.28 (0.19)	0.71 (0.32)*

Note: Visit 1 is 1st office visit when patients were diagnosed with PCOS (baseline). Once PCOS was diagnosed, patients started metformin treatment. Visit 2 was 2nd office visit (1st-2nd month of treatment). Visit 3 was 3rd office visit (3rd- 4th month of treatment). The analysis was adjusted for the effect of medication adherence via the Morisky 8-item medication adherence scale

Abbreviations: PCOS polycystic ovary syndrome, HRQoL Health related Quality of life, SE standard error

*p < 0.05