Although the overall receipt of cancer screening procedures and immunizations in the UCSF LOS was relatively high and comparable to the general population, we observed considerable variation among sociodemographic subgroups. In particular, individuals with SLE who were younger and reported less educational attainment were significantly less likely to receive preventive services. In addition, health system factors, such as the involvement of a generalist provider in care and total physician visits, were also associated with the receipt of preventive health care services in SLE.
Although immunization frequencies in SLE have not previously been reported, our finding that about 60% of eligible patients receive pneumococcal or influenza immunization is consistent with studies in other rheumatic diseases [22
]. The finding that 40% of patients remain unvaccinated is notable given that approximately one-third of deaths in SLE are attributable to infections [23
], and several studies have found that respiratory infections, including those attributable to Streptococcus pneumoniae
, are the leading cause of serious infections in SLE [24
]. We did not investigate specific reasons for non-immunization, which might include patient preferences, contraindications, failure of providers to offer the vaccine, or cost. In SLE, suboptimal immunization frequencies may also partly reflect long-standing concerns about vaccine safety that arose after early reports of fatalities or increased disease activity following immunization [26
]. However, several decades of scientific research have now failed to corroborate these early concerns [28
]. Based on this evidence, recently developed quality indicators for SLE have established influenza and pneumococcal immunization in this population as a minimally acceptable standard of care [13
]. Our study suggests that individuals with lower educational attainment are at particularly high risk of not receiving immunizations, a finding that is consistent with a growing body of evidence that individuals with less education may receive poorer quality health care [29
About one third of patients in our cohort did not receive recommended cancer screening tests. As in the case with immunizations, younger patients and those with less educational attainment were less likely to receive recommended cancer screening. Although we expected that those enrolled in HMOs would be more likely to receive cancer screening given the emphasis of these organizations on preventive care, this was not the case. However, consistent with other recent studies, individuals with a higher number of physician visits were more likely to receive cancer screening services [31
]. No specific cancer surveillance guidelines for SLE have been published to date, although at a minimum, it seems reasonable that SLE patients should receive cancer surveillance tests recommended for the general population. One previous study has examined cancer surveillance rates in Canadian SLE patients using a tertiary-care clinic cohort. In that study, researchers surveyed 146 patients regarding receipt of cancer screening tests in the last year. Unlike our study that found screening rates similar to the general population, rates in that cohort fell well below general population cancer screening rates in Canada [5
Our study also suggests that both a higher number of physician visits and involvement of primary care providers in SLE management are associated with improved preventive health care quality. As short-term mortality from SLE declines and clinical care increasingly shifts toward the long-term prevention and management of co-morbidities and complications, effectively coordinating care between specialists and primary care providers is a priority. Such coordination, however, may prove challenging in SLE, where clinical care often spans multiple specialists who sometimes practice at significant geographic distances from each other [33
]. Increasing awareness among primary care providers about the higher risk of specific long-term complications in SLE, and improving care coordination by specialists caring for SLE patients through various practice innovations, such as automatic reminders in electronic medical records, may help improve the quality of preventive health care in this population.
Studying health services in SLE is challenging given the low prevalence of the disease. Most research to date has drawn from tertiary care specialty clinics, which may not adequately represent the entire population with SLE. Although not a random sample of the population of patients with SLE, our study has attempted to partly address this gap by drawing from community-based sources. Nevertheless, our study has limitations. First, because the LOS participants speak English and have health insurance, we cannot generalize our findings to non-English speaking individuals or those without health insurance - two groups that are at great risk of receiving poorer quality health care. Conducting this research in non-English speaking and indigent populations should be prioritized in future studies. Second, participants in the LOS may not be directly comparable to those in CHIS. Although we had a sufficient number of observations to standardize our sample based on age and education and included only insured individuals in our analyses, additional standardization by potential confounding factors such as race/ethnicity and type of health insurance was not possible. Third, our study did not include at least one variable found in previous research to influence the receipt of preventive services: medical comorbidities [31
]. Incorporating a measure of comorbidity in future studies on the topic is therefore warranted. Fourth, our study did not assess the specific reasons for not receiving preventive services, and therefore we cannot determine whether gaps in care are secondary to patient, provider or health system factors. Finally, our data derive from self-report. Previous studies have demonstrated that self-report is a reasonable, although not perfect, proxy for various preventive health services [31