Does continuity of care improve patient outcomes?

Results

Search yield

We found 5087 candidate titles in our original search. We excluded 4891 titles after examination of the bibliographic citation, which left 196 articles. After examining the full text of these remaining articles, 18 fulfilled our criteria (Table 1). The kappa to measure the preconsensus inter-rater reliability for article selection was 0.93.

Study designs

Of the 18 articles in the final analysis, 12 (67%) were cross-sectional studies,^21-32 five (28%) were cohort studies,^{33- 37} and one (6%) was an RCT.³⁸ In the RCT, subjects were elderly men enrolled in a Veteran’s Administration outpatient clinic. Subjects randomized to the “discontinuity” group had a 33% chance of being scheduled with a different provider at each visit and were also scheduled with a different provider if they had seen the same provider for the previous 2 visits. Subjects in the “continuity” group were scheduled to see the same provider routinely.³⁸

Study populations, providers, and settings

Fifteen of the 18 studies (83%) were conducted in the United States. Ten studies (56%) focused on specific groups of patients: those insured by Medicaid (n=4), adults with diabetes (n=2), multiethnic women, elderly men, adults with seizure disorder, children with chronic diseases, and children and adults with asthma (n=1 each).

Health care providers in these studies included different primary care specialties, such as family medicine (n=4), pediatrics (n=4), general practice (n=2), internal medicine (n=1), and mixed primary care physicians (n=5). One study included pediatric subspecialists. In 5, the SCOC was described for the patient’s “regular physician.”

Methods used to measure SCOC

Table 2 displays the different methods and data sources used to determine SCOC. Data sources included medical records (n=3), medical claims data (n=5), and surveys (n=10). One study calculated SCOC separately using both medical records and a patient survey.²²

Six of the methods used formulas to account for different combinations of factors, such as number of visits, dispersion of providers, and number of visits to a particular provider (see Appendix). There were 8 different methods to determine SCOC based on survey responses, ranging from single item questions^{24, 32} to a 23-item perception of continuity scale.²²

Associations between SCOC and quality or cost of care

Overall, we found no studies documenting any negative effects of increased SCOC on quality or care. Due to the heterogeneity of methods to calculate SCOC and endpoints, we were unable to combine results.

Costs. Two cross-sectional studies examined factors associated with cost of care (Table 1). Increased SCOC measured by the usual provider continuity (UPC) index correlated with increased provider or MCO cost of care (P<.05); however, the results were not significant when SCOC was measured using other indicies.²² Another study found that increased SCOC was associated with decreased total annual health care expenditures.²³

Satisfaction. Although we could not pool results of studies due to heterogeneity, there is a consistent association between SCOC and patient satisfaction, based on the results of 4 studies (Table 1).

Three cross-sectional studies in different settings^{21, 22, 31} found a positive association between increased SCOC and patient satisfaction. However, all 3 studies used subjective methods to determine SCOC. One study that used quantitative methods to measure SCOC (ie, COC index, UPC scale) did not find a statistically significant association with patient satisfaction.²² One RCT found no effect on satisfaction with patient-provider interaction overall (P>.05).³⁸

Patient outcomes. The effect of SCOC seems consistent across studies for patients with chronic conditions who were hospitalized or visited emergency departments (Table 1).

In one RCT, the continuity group had fewer hospital days (5.7 vs. 9.1, P=.02); fewer intensive care days (0.4 vs. 1.4, P=.01); shorter hospital length of stay (15.5 vs. 25.5, P=.008); and lower percentages of emergent hospitalization (20% vs 39%, P=.002) compared with the discontinuity group. Of note, the subjects were all elderly men, of whom 47% had cardiovascular disease and 18% had respiratory disease.³⁸

In 2 cross-sectional and 4 cohort studies, SCOC led to decreased hospitalizations and emergency department use, and to some improvements in preventive health behavior. Half of the studies focused on patients with chronic conditions (asthma or diabetes).^{33, 34, 37} Medicaid claims data analyses suggest that higher SCOC is associated with decreased likelihood of making single and multiple emergency department visits, hospitalizations overall, and hospitalizations for chronic conditions.^{26, 36} However, higher SCOC did not decrease the risk of hospitalization for acute ambulatory care sensitive conditions (eg, gastroenteritis).³⁶

Process of care. For preventive services, 5 cross-sectional studies found that increased SCOC improved receipt of preventive services (Table 1).^{24, 28-30, 32, 33, 35}

Two cross-sectional studies examined the association between SCOC and patient-provider communication.³⁵ One study found that increased SCOC improved communication and patient perception regarding the ability to influence treatment.²⁷ One study on epilepsy care found greater patient ease in talking to the physician.²⁵

One RCT found no differences in scheduled or unscheduled clinic visits, specialty referrals, or receipt of preventive care procedures such as blood pressure measurement, weight assessment, or assessment of smoking status (P>.05).³⁸