Box 1. How domains in the questionnaire were operationalised into explaining variables in the analyses

Domains	Items	Description	Dichotomisation
Meeting structure	Scheduled meetings	The occurrence of scheduled meetings (versus ad hoc conversations)	Scheduled meetings: Yes/no
	Interdisciplinary meetings	Frequency of GP and staff meetings: Weekly/monthly/quarterly/rarer/never	Weekly: Yes/no
	GP meetings	Frequency of sole GP meetings: Weekly/monthly/quarterly/rarer/never	Weekly: Yes/no
	Educational meetings	Frequency of meetings aimed at learning about a specific topic: Weekly/monthly/quarterly/rarer/never	Weekly: Yes/no
	Formalised meetings	A formal agreement about agenda, mediator and/or minutes in relation to meetings. For each factor is stated: Always/often/sometimes/rarely/never	Always for all factors: Yes/no
Standardised processes of care	Practice protocols	The extent to which practice protocols are developed in the practice: In a range of areas of disease/in a few areas of disease/none at all	In a range of areas of disease: Yes/no
	Standard laboratory requisition formulas	The extent to which standard laboratory requisitions formulas are developed in the practice: In a range of areas of disease/in a few areas of disease/none at all	In a range of areas of disease: Yes/no
	Standard phrases in the EMR	The extent to which standard phrases in the EMR are developed in the practice: In a range of areas of disease/in a few areas of disease/none at all	In a range of areas of disease: Yes/no
Task differentiation among GPs	Responsibilities for medical update	The extent to which responsibilities regarding medical update (on for instance COPD, DM and IHD) are based on a formal agreement in the practice: yes/informal/no	Formal agreement: Yes/no

COPD = chronic obstructive pulmonary disease. DM = diabetes mellitus. EMR = electronic medical record. IHD = ischemic heart disease.