Not less than 14 days before the expiration of an initial, second, or continuing order of involuntary mental health treatment issued under section 472a or section 485a, a hospital director or an agency or mental health professional supervising an individual's assisted outpatient treatment shall file a petition for a second or continuing order of involuntary mental health treatment if the hospital director or supervisor believes the individual continues to be a person requiring treatment and that the individual is likely to refuse treatment on a voluntary basis when the order expires. The petition shall contain a statement setting forth the reasons for the hospital director's or supervisor's or their joint determination that the individual continues to be a person requiring treatment, a statement describing the treatment program provided to the individual, the results of that course of treatment, and a clinical estimate as to the time further treatment will be required. The petition shall be accompanied by a clinical certificate executed by a psychiatrist.