TableĀ 1

Primary healthcare units by regional health administrations in the Portuguese National Health Service sampled for the study of preventive health services implemented by primary healthcare physicians

Number of primary healthcare units in the Portuguese National Health ServiceNumber of primary healthcare units (clusters) selected for our sample
Northern regional health administration38138
Centre regional health administration656
Lisbon and Tagus Valley regional health administration38038
Alentejo regional health administration576
Algarve regional health administration192