Demographic characteristics and prior utilization experience of HMO disenrollees compared with total membership.

In the 2 months immediately after a premium rate increase, the Genesee Valley Group Health Association (Group Health) lost over 600 subscriber contracts. A survey was conducted to determine the reasons for disenrollment and compare the demographic and utilization characteristics of disenrollees with those of all members during the previous calendar year. The disenrollees were members of smaller families and were concentrated in a younger adult age group (15 to 35 years). The disenrollee ambulatory utilization rate was 14.5 per cent lower than for all members and their inpatient utilization (days/1,000) rate was 35 per cent lower. While maternity/nursery days were higher for disenrollees, medical/surgical days were 56 per cent lower. Age-adjusted medical/surgical days were 63.9 per cent lower. Although there was concern about possible adverse effects of a rate increase, the 1980 group Health inpatient utilization rates were virtually the same as for 1979, the year before the rate increase studied.