Ion-refresher question

Here what I've done. Probably can be optimized or done differently. I am opened for other suggestions

  onPageLoaded() {
    this.refresh();
  }

  refresh() {
    return new Promise((resolve, reject) => {
      Observable.forkJoin(
        this._service1.retrieveData(),
        this._service2.retrieveData(),
        this._service3.retrieveData()
      ).subscribe(
        data => {
         ...
    });
  }

  doRefresh(refresher) {
    this.refresh().then((success) => refresher.complete(), (error)=> refresher.complete());

  }