=== versions === python 3.12.0 | osmnx 2.1.1 | networkx 3.7 | access 1.1.10.post3 | geopandas 1.2.0 | scipy 1.18.1 | numpy 2.5.4 | pandas 3.1.0 === study area === Cornwall: 3,549 km2 | with a 25 km buffer: 14,979 km2 (much of it sea) 3,183 output areas in the buffered study area, 980,749 residents (Census 2021) in Cornwall: 1,847 OAs, 570,334 residents; in the buffer (Devon): 1,336 OAs, 410,415 residents === GP practices === England: 6,124 practices in the October 2026 list; 6,143 in the August 2026 workforce file 142 practices with TR, PL or EX postcodes; 0 postcodes not found 92 practices in the buffered study area: 54 in Cornwall, 38 in Devon practices with no GP FTE in the workforce file: 0 Cornwall: 600,920 registered patients, 409.0 GP FTE (0.681 per 1,000 registered patients); 1,493 patients per GP FTE across the study area Cornwall practice size: median 9,070 patients, median 7.3 GP FTE === road network (OpenStreetMap -> OSMnx) === 46,322 nodes, 105,181 edges (largest strongly connected component); 6 s edge speeds: median 40 km/h; 4.0% of edges at 96 km/h or more dropping 3 OA(s) more than 2 km from the network: E00102210, E00102212, E00102175 (781 residents, in Cornwall: 0) snap distance: OA centroids median 40 m, 95th percentile 241 m, max 1903 m; practices median 49 m, max 200 m travel-time matrix: 3,180 OAs x 92 practices in 0.4 s; unreachable pairs: 0 === nearest practice === Cornwall residents' drive time to the nearest GP practice: mean 3.8 min, median 3.0 min, max 14.7 min more than 10 min: 15,215 residents (2.7%) more than 15 min: 0 residents (0.0%) more than 20 min: 0 residents (0.0%) Cornwall OAs whose nearest practice is in Devon: 12 (3,398 residents) === 2SFCA and E2SFCA (access package) === cost table: 189,308 OA-practice pairs within 60 min 2sfca: numpy vs access max abs difference 2.22e-16 e2sfca: numpy vs access max abs difference 6.66e-16 g2sfca: numpy vs access max abs difference 4.44e-16 Cornwall overall: 0.717 GP FTE per 1,000 residents (Cornwall practices / Cornwall residents) 2sfca mean 0.721 | median 0.749 | OA 10th-90th pct 0.442-0.935 | min 0.228 max 1.111 | CV 0.27 e2sfca mean 0.702 | median 0.692 | OA 10th-90th pct 0.434-0.942 | min 0.178 max 1.116 | CV 0.29 g2sfca mean 0.704 | median 0.696 | OA 10th-90th pct 0.447-0.932 | min 0.215 max 1.060 | CV 0.25 Spearman rank correlation, nearest-practice time vs E2SFCA (Cornwall OAs): -0.22 === catchment threshold sensitivity (2SFCA) === 10 min: OA 10th-90th pct 0.380-1.101 | CV 0.44 | residents with no practice in reach 15,215 | Spearman vs 30 min 0.19 15 min: OA 10th-90th pct 0.447-1.065 | CV 0.32 | residents with no practice in reach 0 | Spearman vs 30 min 0.54 20 min: OA 10th-90th pct 0.409-1.012 | CV 0.34 | residents with no practice in reach 0 | Spearman vs 30 min 0.77 30 min: OA 10th-90th pct 0.442-0.935 | CV 0.27 | residents with no practice in reach 0 | Spearman vs 30 min 1.00 45 min: OA 10th-90th pct 0.616-0.966 | CV 0.18 | residents with no practice in reach 0 | Spearman vs 30 min 0.32 60 min: OA 10th-90th pct 0.561-1.037 | CV 0.25 | residents with no practice in reach 0 | Spearman vs 30 min -0.11 === edge effects at the Cornwall-Devon border === population-weighted mean E2SFCA (GP FTE per 1,000) by distance from the Devon border (km): Cornwall only + Devon practices only + Devon practices and residents residents band 0-5 0.568 3.750 0.640 48791.0 5-10 0.549 3.211 0.549 33329.0 10-20 0.681 1.782 0.512 39396.0 20-40 0.655 0.673 0.596 81850.0 40+ 0.770 0.770 0.768 366968.0 Cornwall only: vs full buffer, OAs within 10 km of the border: median -7.7%, range -48.0% to +79.6%; beyond 40 km max |diff| 3.7% + Devon practices only: vs full buffer, OAs within 10 km of the border: median +413.3%, range +55.4% to +2384.0%; beyond 40 km max |diff| 3.7% === urban and rural areas === Rural: 311,640 residents (55%) | nearest practice 4.8 min | 2SFCA 0.684 | E2SFCA 0.643 GP FTE per 1,000 Urban: 258,694 residents (45%) | nearest practice 2.5 min | 2SFCA 0.766 | E2SFCA 0.773 GP FTE per 1,000 lowest-access decile of OAs (E2SFCA < 0.434): 49,119 residents, 0% urban, mean nearest-practice time 6.1 min === figures === saved 01-study-area.png, 02-nearest-practice-time.png, 03-2sfca-e2sfca.png, 04-decay-and-threshold.png, 05-edge-effects.png, 06-time-vs-access.png