public function getFilterList()
    {
        $cacheId = __CLASS__ . '_' . __FUNCTION__;

        $output = $this->cache->load($cacheId);
        if ($output) {
            return $output;
        }

        $output = $this->db->fetchPairs("SELECT gaf_id, COALESCE(gaf_manual_name, gaf_calc_name) "
                . "FROM gems__appointment_filters WHERE gaf_active = 1 ORDER BY gaf_id_order");

        $this->cache->save($output, $cacheId, array('appointment_filters'));

        return $output;
    }