Nutrition guidance by primary-care physicians: LISREL analysis improves understanding.

BACKGROUND When determinants of nutrition guidance practices for primary care physicians (PCPs) are identified, the key question remains: what is the mechanism of action? This knowledge is essential in order to understand how PCPs practice nutrition guidance. METHODS Mail questionnaires (result of focus-group discussions and in-depth interviews) were sent to a nationwide random sample of 1,000 PCPs in the Netherlands, who had been in practice for between 5 and 15 years (633 respondents). The mechanism of action of determinants of nutrition guidance practices of PCPs was identified by means of linear structural relationship analysis (LISREL) using a postulated model. RESULTS The postulated model on the mechanism of action was confirmed. The model demonstrates that nutrition guidance practices of PCPs are directly and significantly based on a few predisposing factors; driving forces and perceived barriers may act as significant intermediary variables. The predisposing factors, driving forces, and perceived barriers were identified. CONCLUSION Policies to improve nutrition guidance practices of PCPs may, in the future, benefit from a LISREL model analysis of determinants of these practices to become more effective. Using multiple regression analysis to ascertain the determinants of these practices could result in missing important predisposing factors and "hidden" intermediary factors and lead, therefore, to an incomplete understanding of the mechanism of action.