Manuti et al. BMC Public Health 2010, 10:350 http://www.biomedcentral.com/1471-2458/10/350 previous studies conducted by some of us in the same area [60-62]. Regarding subjects’ socio-demographic characteristics, in accord with several studies [3,47,55-59], we found that gender and age were related to disparities of deliv- ery of certain clinical preventive services. Elderly men were more likely to have blood pressure checks and recommended routine influenza and pneumococcal vac- cinations, but elderly women were less likely to receive mammography than younger women; moreover, females were less likely to have access to screening for drinking problems and to sigmoidoscopy or colonoscopy. The reasons for the observed demographic disparities are complex and vary according to outcomes. For instance, age-difference may be attributable to the awareness that the elderly are more susceptible to flu or pneumococcal disease [51] and hypertension [25], whereas early diag- nosis of breast cancer has an attributable best benefit for younger groups [29]. Gender-related differences for screening for drinking problems may relate to perceived differences in alcohol intake between males and females [59] while colon cancer screening may reflect the prefer- ence among women to avoid invasive tests [58]. Contrary to expectations, level of education unevenly influenced access to clinical preventive services. A key finding was that women with higher level of education were more likely to have access to Pap smear but less access to colonoscopy and blood pressure check. A pre- vious survey by the National Institute of Statistics (ISTAT) [63], showed that in Italy, particularly in the South, the use of the Pap test is more frequent among women with higher education level. Previous studies also show that disparities in levels of education (and its cognate, health literacy) is directly proportional to dispa- rities in preventive care services [3,47,64-66]. We found, contrary to that, that higher level of education does not lead to a better access to preventive services as a whole, probably because high education level alone is not suffi- cient to ensure the necessary awareness of the impor- tance of preventive care. In the healthcare system currently instituted in Southern Italy, the more educated the patient the less likely he is to consider the PCP as the central figure to consult when needed and this is confirmed by our results which show that more edu- cated subjects prefer private specialists, and the PCP is consulted mainly for drug prescription[61]. The finding that screening for alcohol problem was sig- nificantly associated with alcohol intake is consistent with the results of a recent survey [67], that demon- strated that physicians try to motivate patients to address alcohol problems especially if they are heavy drinkers. Finally, consistent with the national ISTAT data [68] revealing a distinctive North-South gradient, we found Page 8 of 10 that the PCS-12 and MCS- 12 mean scores were lower than Italian general population norms, with a difference score of -2.7 and -5, respectively [22]; moreover Wallace et al [69] reports that the low scores are influenced by lack of social support and we may suggest that this sociological factor influences our current results as well. Of some interest, the health summary scores do not correspond significantly with the outcomes investigated, except for the PCS-12 score which influenced adult vac- cinations. Holm et al [36] also found that poor health led most frequently to eventual vaccination. Even tough we provide perceptive examinations of access and delivery of preventive care, our findings must be interpreted within the context of the study’s limita- tions. The data were cross-sectional, patient-based and self-reported. Self reports, compared to other major data sources, such as medical records, may result in overesti- mates or underestimates of quality of preventive care. Stange et al [70], who compared medical records review and patient questionnaire methods to the gold standard of direct observation of the outpatient visit, showed that medical record review is preferable to patient question- naire only with respect to the variables for which there are limitations in patient understanding or knowledge. Patient reporting is a more valid measure for other areas of service delivery, such as screening and counsel- ing on health habits items, and reflect high sensitivity toward certain physical examination and cancer screen- ing items that would be overt and memorable to a patient, such as Pap smear and breast and pelvic exami- nations; therefore, we do not think that our method of measuring the delivery of clinical preventive services may represent a substantial problem for the interpreta- tion of our results. The Rand Quality Indicators on health habits are recommended as a one time question and it may be that some patients would satisfy the quality indicator but may not remember that their PCP asked about them many years ago. In addition we do not have data on drinking problem or drug abuse and individuals may better remember services delivered for an actual pro- blem rather than for prevention. Moreover, it should also be pointed out that if patients were only seen one time for an urgent issue it would be unlikely that they received these services. Our results have significant implications for health care policymakers, since the indicators we used demon- strated to be a useful tool for monitoring access to clini- cal preventive services, assessing effectiveness of state- wide preventive health program, improve quality and reduce barriers to access to preventive health care through the implementation of future interventions in this population.