My response to this question is confined to the Civil Service, as my responsibility in this matter does not extend to the wider public service. In so far as the Civil Service is concerned, a person who has more than 56 days' sick leave in the preceding period of four years is considered unsuitable for promotion. This rule is applied in a flexible fashion. Absences for minor curative or "repair" operations, or absences due to non-recurring illnesses, may be discounted. If the candidate's sick leave record shows an improvement in the latter part of the four-year period, there is discretion to give him or her the benefit of the doubt.
I do not propose to change the current rules.