Correction

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

  1. 1)

    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.’

  2. 2)

    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’.

Table 3 Mixed effect model analysis of metformin effect on general HRQoL outcome measured via WHOQOL-Bref
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Table 4 Mixed effect model analysis of metformin effect on PCOS-specific HRQoL measured via Chi-PCOSQ
Full size table

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).