We used linear regression to analyze factors associated with visit duration and to calculate the minutes attributed to each factor. Models were adjusted for specific therapeutic and diagnostic techniques performed at the visit. MD visit duration was obtained from published 1995 ± 96 National Ambulatory Medical Care Survey results. RESULTS: Mean visit duration for CP was 21.5 minutes (SE=0.8) and for AC 56.6 minutes (SE=0.7), compared to 18.9 minutes (SE=0.5) for a visit to an internist (p=.006 for CP vs. MD, p < .001 for AC vs. MD). AC spent more time with patients at self-pay visits, new patient visits, and visits for flares of chronic problems, adding 4.7, 4.0, and 2.4 minutes respectively. AC visits for anxiety/depression were 2.6 minutes longer, with a mean duration of 50.2 minutes, compared to 32.6 minutes for MD visits for the same problem (p < .001). For CP visits, significantly more time was spent with new patients, when there was communication with other providers, and with patients receiving concurrent care from an MD, adding 6.7, 3.2 and 2.3 minutes to each visit, respectively. CP visits for wellness and chronic problems were shorter than acute visits, by 3.2 and 4.3 minutes, respectively. Patient age, sex, and reason for visit (i.e. back or neck symptom) did not affect CP visit duration. Visits in Arizona were, on average, 3.0 minutes longer than those in Massachusetts. CONCLUSION: Acupuncturists spend significantly more time with patients on an average visit compared to physicians. Chiropractors report spending more time than physicians, although this difference is small and may be due to differences in how the data were collected. CP visit duration suggests regional variation. Payment source, communication with other providers, psychosocial reason for visit, and acuity of visit are important correlates of CP or AC visit duration. These trends towards``vertical integration'' (VI) have been studied primarily in terms of their financial causes and impact. Effect on clinical care is unknown. This study examines whether hospital VI impacts continuity and timing of clinical process of care for acute stroke patients. METHODS: A survey was fielded in mid-2000 of the primary stroke providers at all acute care hospitals with acute stroke discharges in California in 1998. Survey findings were linked to California state hospital facility reports and individual patient discharge records for 1998. Multiple regression models were used to examine the association of highest level of integration (internal rehab unit (IR), formal control of external unit (FER), informal agreement of external unit (IER), and no agreement (NoR)) with service availability, reported interventions, and patient outcome, controlling for other hospital features and patient demographics. RESULTS: Surveys were completed for 256/374 (68%) of hospitals that admitted stroke patients in 1998 and that were still open in 2000. Non-respondent hospitals were smaller, rural, or independent. Among respondent hospitals, level of integration was 20% IR, 7% FER, 15% IER, and 58% NoR. Greater integration was significantly associated with stated greater use of acute care guidelines, hours of rehab care during acute hospitalization, continuity of providers between acute and post-acute care, management by specialists, and use of common medical information systems. When linked to patient records, level of integration did not predict initiation of rehab during hospitalization or in-hospital mortality, but was associated with increased likelihood of discharge to post-acute rehab.