C. VAN DE VOORDE ET AL going to see a specialist in his office, as specialists trated in the last 3 years of the observation pe are directly accessible without a GP referral. riod, the years prior to the change are useful in Again, the latter is somewhat more expensive estimating any underlying trends. Figures I(a) (higher fee and higher co-payment rate), but is 3(b) serve to illustrate some of the overall time possibly perceived as higher quality too. It is well trends and changes in the utilization,and the known that, for common specialities,, like, for co-payments for the three types of care for the example, gynaecologists, paediatricians, dermatol- general population (in Figure 1(a)and(b),the ogists, ophthalmologists etc, a la share of wopi (in Figure 2(a)and(b)and the low consultations in Belgium occur without a GP Income (1.e referral. In Belgium (unlike the situation in empt) WoPI (in Figure 3(a) and France [14]), all GPs deliver home visits, and (b). They show (i that the GP home visits are there are no systematic differences in the quality most prevalent among the woPl, but especia of services offered by GPs during home and office among those on low incomes, (i) that for the firs two categories of insured, a(negative)deviation from the trend occurred for all types of care immediately after the co-payment rise in 1994, (iii) that little or nothing seems to have happened for the exempt group, for whom co-payments were We have used time series data on three categories not raised, (iv) that, in contrast to the trends for of outpatient care: GP home visits, GP office most other types of utilization, the trend for GP consultations and specialist office consultations. home visits in the general population was already Although most of the price variation is concen- downward prior to the 1994 change 3,0 e-GP home visits 2.0 — GP office visits -specialist visits 1.6 GP office visits r specialist visits year Figure 1.(a) Physician utilization rates, general population; (b)co-payments, general population Copyright a 2001 John Wiley Sons, Ltd Health Econ.10:457-471(2001)462 C. VAN DE VOORDE ET AL. going to see a specialist in his office, as specialists are directly accessible without a GP referral. Again, the latter is somewhat more expensive (higher fee and higher co-payment rate), but is possibly perceived as higher quality too. It is well known that, for ‘common specialities’, like, for example, gynaecologists, paediatricians, dermatol￾ogists, ophthalmologists etc., a large share of consultations in Belgium occur without a GP referral. In Belgium (unlike the situation in France [14]), all GPs deliver home visits, and there are no systematic differences in the quality of services offered by GPs during home and office visits. Trends We have used time series data on three categories of outpatient care: GP home visits, GP office consultations and specialist office consultations. Although most of the price variation is concen￾trated in the last 3 years of the observation pe￾riod, the years prior to the change are useful in estimating any underlying trends. Figures 1(a)– 3(b) serve to illustrate some of the overall time trends and changes in the utilization, and the co-payments for the three types of care for the general population (in Figure 1(a) and (b)), the WOPI (in Figure 2(a) and (b)) and the low￾income (i.e. exempt) WOPI (in Figure 3(a) and (b)). They show (i) that the GP home visits are most prevalent among the WOPI, but especially among those on low incomes, (ii) that for the first two categories of insured, a (negative) deviation from the trend occurred for all types of care immediately after the co-payment rise in 1994, (iii) that little or nothing seems to have happened for the exempt group, for whom co-payments were not raised, (iv) that, in contrast to the trends for most other types of utilization, the trend for GP home visits in the general population was already downward prior to the 1994 change. Figure 1. (a) Physician utilization rates, general population; (b) co-payments, general population Copyright © 2001 John Wiley & Sons, Ltd. Health Econ. 10: 457–471 (2001)