Measuring continuity in primary care: how it is done and why it matters Free

Description of continuity of care measures.

Measure	Assigned PCP	Perspective	Methodology²²	Number of Physicians	Formula
Usual Provider of Care (UPC)²⁹	Yes	Patient	Density	No	$\frac{\begin{array}{l} v_{i} \end{array}}{V}$
Bice-Boxerman Continuity of Care (BB-COC)³⁰	No	Patient	Dispersion	Yes	$\frac{\begin{array}{l} (\sum_{i = 1}^{p} {v_{i}}^{2}) \end{array} - V}{V (V - 1)}$
Modified Modified Continuity Index (MMCI)³¹	No	Patient	Dispersion	Yes	$\frac{1 - (\frac{P}{V + 0.1})}{1 - (\frac{1}{V + 0.1})}$
Sequential Continuity of Care Index (SECON)³³	No	Patient	Sequence	Yes	$\frac{\begin{array}{l} (\sum_{i = 1}^{V - 1} s_{i}) \end{array}}{V - 1}$
Continuity for Physician (PHY)²¹	Yes	Physician	Density	No	$\frac{c}{V}$

Measure	Assigned PCP	Perspective	Methodology²²	Number of Physicians	Formula
Usual Provider of Care (UPC)²⁹	Yes	Patient	Density	No	$\frac{\begin{array}{l} v_{i} \end{array}}{V}$
Bice-Boxerman Continuity of Care (BB-COC)³⁰	No	Patient	Dispersion	Yes	$\frac{\begin{array}{l} (\sum_{i = 1}^{p} {v_{i}}^{2}) \end{array} - V}{V (V - 1)}$
Modified Modified Continuity Index (MMCI)³¹	No	Patient	Dispersion	Yes	$\frac{1 - (\frac{P}{V + 0.1})}{1 - (\frac{1}{V + 0.1})}$
Sequential Continuity of Care Index (SECON)³³	No	Patient	Sequence	Yes	$\frac{\begin{array}{l} (\sum_{i = 1}^{V - 1} s_{i}) \end{array}}{V - 1}$
Continuity for Physician (PHY)²¹	Yes	Physician	Density	No	$\frac{c}{V}$

PCP, Primary care provider

V = total number of visits

v_i = number of visits to provider i, e.g. PCP, or i^th different provider, where i = 1, 2, …, P

P = total number of providers

s_i = 1, if same provider is seen at sequential visits, = 0 otherwise. V visits generate V-1 sequential pairs of visits, upon which to assign values to s_i.

c = number of visits with panel patients

Table 1.

Description of continuity of care measures.

Measure	Assigned PCP	Perspective	Methodology²²	Number of Physicians	Formula
Usual Provider of Care (UPC)²⁹	Yes	Patient	Density	No	$\frac{\begin{array}{l} v_{i} \end{array}}{V}$
Bice-Boxerman Continuity of Care (BB-COC)³⁰	No	Patient	Dispersion	Yes	$\frac{\begin{array}{l} (\sum_{i = 1}^{p} {v_{i}}^{2}) \end{array} - V}{V (V - 1)}$
Modified Modified Continuity Index (MMCI)³¹	No	Patient	Dispersion	Yes	$\frac{1 - (\frac{P}{V + 0.1})}{1 - (\frac{1}{V + 0.1})}$
Sequential Continuity of Care Index (SECON)³³	No	Patient	Sequence	Yes	$\frac{\begin{array}{l} (\sum_{i = 1}^{V - 1} s_{i}) \end{array}}{V - 1}$
Continuity for Physician (PHY)²¹	Yes	Physician	Density	No	$\frac{c}{V}$

Measure	Assigned PCP	Perspective	Methodology²²	Number of Physicians	Formula
Usual Provider of Care (UPC)²⁹	Yes	Patient	Density	No	$\frac{\begin{array}{l} v_{i} \end{array}}{V}$
Bice-Boxerman Continuity of Care (BB-COC)³⁰	No	Patient	Dispersion	Yes	$\frac{\begin{array}{l} (\sum_{i = 1}^{p} {v_{i}}^{2}) \end{array} - V}{V (V - 1)}$
Modified Modified Continuity Index (MMCI)³¹	No	Patient	Dispersion	Yes	$\frac{1 - (\frac{P}{V + 0.1})}{1 - (\frac{1}{V + 0.1})}$
Sequential Continuity of Care Index (SECON)³³	No	Patient	Sequence	Yes	$\frac{\begin{array}{l} (\sum_{i = 1}^{V - 1} s_{i}) \end{array}}{V - 1}$
Continuity for Physician (PHY)²¹	Yes	Physician	Density	No	$\frac{c}{V}$

PCP, Primary care provider

V = total number of visits

v_i = number of visits to provider i, e.g. PCP, or i^th different provider, where i = 1, 2, …, P

P = total number of providers

s_i = 1, if same provider is seen at sequential visits, = 0 otherwise. V visits generate V-1 sequential pairs of visits, upon which to assign values to s_i.

c = number of visits with panel patients

Usual provider of care

The most common way to measure patients’ COC is a simple proportion: the number of visits with PCP divided by the total number of visits. This formula is known as Usual Provider of Care (UPC).³⁰ The benefit of a density measure like UPC is its simplicity; it’s easy to calculate and easy to interpret. However, UPC requires knowledge of patients’ assigned PCP, which may not be accessible outside of the EHR and may be out of date if not routinely updated. Researchers without access to EHR data use claims-based data, which often lacks PCP designation, so PCP will be retrospectively assigned based on the provider most often seen, or first seen within the study period. The simplicity of UPC has several shortcomings. UPC does not account for the frequency of visits within the study period, which means patients’ level of healthcare utilization is ignored. For example, a UPC of 0.5 could be the result of a patient seeing their PCP 1 out of 2 visits, or 6 out of 12 visits (Table 2). Nor does it account for the number of different providers a patient may have had visits with (i.e. dispersion). Discontinuity can negatively affect patients’ trust and satisfaction with their healthcare, and as patients see a larger number of providers, the risk likely grows.³ Depending on the outcome(s) of interest, it may be beneficial to control for patients’ total number of visits as a way to account for differences in health care utilization.

Table 2.

Examples of patient visit scenarios and corresponding continuity of care values by measure.

Number of visits	Number of providers	Visits with providers^a, in sequential order	UPC	BB-COC	MMCI	SECON
2	2	A-B	0.50	0	0.10	0
4	2	A-A-B-B	0.50	0.33	0.67	0.67
4	3	A-A-B-C	0.50	0.17	0.36	0.33
4	4	A-B-C-D	0.25	0	0.03	0
12	2	A-A-A-A-A-A-B-B-B-B-B-B	0.50	0.46	0.91	0.91
12	2	A-A-A-A-A-A-A-A-A-A-A-B	0.92	0.83	0.91	0.91
12	3	A-A-A-A-A-A-B-B-B-C-C-C	0.50	0.32	0.82	0.82
12	3	A-A-A-A-B-B-B-B-C-C-C-C	0.33	0.27	0.82	0.82
12	7	A-A-A-A-A-A-B-C-D-E-F-G	0.50	0.23	0.46	0.45

Number of visits	Number of providers	Visits with providers^a, in sequential order	UPC	BB-COC	MMCI	SECON
2	2	A-B	0.50	0	0.10	0
4	2	A-A-B-B	0.50	0.33	0.67	0.67
4	3	A-A-B-C	0.50	0.17	0.36	0.33
4	4	A-B-C-D	0.25	0	0.03	0
12	2	A-A-A-A-A-A-B-B-B-B-B-B	0.50	0.46	0.91	0.91
12	2	A-A-A-A-A-A-A-A-A-A-A-B	0.92	0.83	0.91	0.91
12	3	A-A-A-A-A-A-B-B-B-C-C-C	0.50	0.32	0.82	0.82
12	3	A-A-A-A-B-B-B-B-C-C-C-C	0.33	0.27	0.82	0.82
12	7	A-A-A-A-A-A-B-C-D-E-F-G	0.50	0.23	0.46	0.45

^aEach letter represents a distinct provider.

All measure values range from 0 to 1.

BB-COC, Bice-Boxerman Continuity of Care; MMCI, Modified Modified Continuity Index; SECON, Sequential Continuity of Care Index; UPC, Usual Provider Continuity.

Table 2.

Examples of patient visit scenarios and corresponding continuity of care values by measure.

Number of visits	Number of providers	Visits with providers^a, in sequential order	UPC	BB-COC	MMCI	SECON
2	2	A-B	0.50	0	0.10	0
4	2	A-A-B-B	0.50	0.33	0.67	0.67
4	3	A-A-B-C	0.50	0.17	0.36	0.33
4	4	A-B-C-D	0.25	0	0.03	0
12	2	A-A-A-A-A-A-B-B-B-B-B-B	0.50	0.46	0.91	0.91
12	2	A-A-A-A-A-A-A-A-A-A-A-B	0.92	0.83	0.91	0.91
12	3	A-A-A-A-A-A-B-B-B-C-C-C	0.50	0.32	0.82	0.82
12	3	A-A-A-A-B-B-B-B-C-C-C-C	0.33	0.27	0.82	0.82
12	7	A-A-A-A-A-A-B-C-D-E-F-G	0.50	0.23	0.46	0.45

Number of visits	Number of providers	Visits with providers^a, in sequential order	UPC	BB-COC	MMCI	SECON
2	2	A-B	0.50	0	0.10	0
4	2	A-A-B-B	0.50	0.33	0.67	0.67
4	3	A-A-B-C	0.50	0.17	0.36	0.33
4	4	A-B-C-D	0.25	0	0.03	0
12	2	A-A-A-A-A-A-B-B-B-B-B-B	0.50	0.46	0.91	0.91
12	2	A-A-A-A-A-A-A-A-A-A-A-B	0.92	0.83	0.91	0.91
12	3	A-A-A-A-A-A-B-B-B-C-C-C	0.50	0.32	0.82	0.82
12	3	A-A-A-A-B-B-B-B-C-C-C-C	0.33	0.27	0.82	0.82
12	7	A-A-A-A-A-A-B-C-D-E-F-G	0.50	0.23	0.46	0.45

^aEach letter represents a distinct provider.

All measure values range from 0 to 1.

BB-COC, Bice-Boxerman Continuity of Care; MMCI, Modified Modified Continuity Index; SECON, Sequential Continuity of Care Index; UPC, Usual Provider Continuity.

Bice-Boxerman Continuity of Care

The Bice-Boxerman Continuity of Care Index (BB-COC) is a density measure that was developed to account for the shortcomings of UPC. Specifically, it considers patients’ number of visits and number of providers seen within the study period.³¹ In addition, BB-COC does not require knowledge of the assigned PCP and can effectively be applied to claims-based datasets. The BB-COC formula, however, is complex and ideally run by an analyst. Interpreting BB-COC values is also less straightforward than UPC. BB-COC is not a proportion measure but an index that accounts for the number of visits, the number of different providers, and the distribution of visits between providers. As a result, BB-COC will equal 0 until a patient has seen a specific provider at least 2 times (Table 2). The BB-COC emphasizes the importance of seeing the same provider(s) more frequently. As seen in the Table 2 examples, BB-COC is able to quantify the nuances of COC but may underestimate COC for patients with just 2 or 3 visits.

Modified Modified Continuity Index

The Modified Modified Continuity Index (MMCI), an iteration of the earlier Modified Continuity Index developed by Godkin and Rice,³² aims to provide a more easily interpreted value than BB-COC, and uses a simpler formula.³³ Similar to BB-COC, MMCI is a dispersion measure that accounts for both the number of providers seen and the total number of visits. Both dispersion measures share similar strengths and weaknesses. However, while both BB-COC and MMCI take into account the number of different providers a patient has seen, the MMCI formula was designed so that it has less of an impact on the COC estimate. As a result, the creators of the MMCI suggest it is more suitable for residency clinics, where the odds are higher that a patient sees several of the many part time faculty and residents. The MMCI is also proposed to provide a more intuitive measure of COC, particularly with high total visit numbers (Table 2). Compared to BB-COC and UPC, MMCI usually results in higher COC calculations. As the number of providers increases MMCI drops below UPC at a certain point because it captures the increasing discontinuity of seeing multiple providers. Overall, the MMCI provides a nuanced measure of COC, but its ease of interpretation is similar to BB-COC.

Sequential Continuity of Care Index

The Sequential Continuity of Care Index (SECON) is unique among the COC measures discussed thus far, as it is a sequence measure and evaluates how often a patient is seeing the same provider consecutively.³⁴ The temporal aspect of COC captured by SECON is particularly beneficial for studies interested in evaluating the effect of continuity on follow-up care for acute and chronic conditions. Similar to dispersion measures, SECON accounts for the number of visits, the number of different providers, and does not require an assigned PCP, but SECON does not account for how many visits occurred with each provider. Instead, SECON solely evaluates, chronologically, how many times a patient switches providers (Tables 2 and 3) Interpretation of SECON values is not as intuitive as UPC, and its complex calculation limits its accessibility to clinicians without analyst support. Further, because SECON does not account for how many visits were with each provider it may not fully capture the patient experience, as seen in the examples in Table 3.

Table 3.

Examples of patient scenarios with 12 visits, 6 with provider A and 6 with provider B, and the corresponding Sequential Continuity of Care Index values.

Number of visits	Number of providers	Visits with providers ^a, in sequential order	SECON
12	2	A-A-A-A-A-A-B-B-B-B-B-B	0.91
12	2	A-A-B-B-A-A-B-B-A-A-B-B	0.55
12	2	A-B-A-B-A-B-A-B-A-B-A-B	0

Number of visits	Number of providers	Visits with providers ^a, in sequential order	SECON
12	2	A-A-A-A-A-A-B-B-B-B-B-B	0.91
12	2	A-A-B-B-A-A-B-B-A-A-B-B	0.55
12	2	A-B-A-B-A-B-A-B-A-B-A-B	0

^aEach letter represents a distinct provider.

Measure values range from 0 to 1.

SECON, Sequential Continuity of Care Index

Table 3.

Examples of patient scenarios with 12 visits, 6 with provider A and 6 with provider B, and the corresponding Sequential Continuity of Care Index values.

Number of visits	Number of providers	Visits with providers ^a, in sequential order	SECON
12	2	A-A-A-A-A-A-B-B-B-B-B-B	0.91
12	2	A-A-B-B-A-A-B-B-A-A-B-B	0.55
12	2	A-B-A-B-A-B-A-B-A-B-A-B	0

Number of visits	Number of providers	Visits with providers ^a, in sequential order	SECON
12	2	A-A-A-A-A-A-B-B-B-B-B-B	0.91
12	2	A-A-B-B-A-A-B-B-A-A-B-B	0.55
12	2	A-B-A-B-A-B-A-B-A-B-A-B	0

^aEach letter represents a distinct provider.

Measure values range from 0 to 1.

SECON, Sequential Continuity of Care Index

Continuity for physician

While the focus of this brief is on the multiple ways of measuring patient COC, provider COC is an important measure, especially when measured concurrently with patient COC. Similar to UPC, Continuity for Physician (PHY) is a proportional measure from the provider’s perspective: the number of visits with panel patients divided by the total number of visits.¹⁹ Comparing and contrasting patient and provider COC can help researchers and clinicians identify opportunities for interventions within the clinic setting, e.g. panel management and patient scheduling protocols. Providers who are over-panelled will have high provider COC and low patient COC because the demand for visits with them is greater than the slots available. While providers who are new to a practice, with a small panel size compared to their visit availability, will have high patient COC but low provider COC.

Conclusions

This brief describes 4 of the most common measures of patient COC and the primary measure for provider COC. Each has strengths and weaknesses, therefore, context and resources play a key role in determining which measure is most appropriate. Clinics and departments interested in evaluating COC for internal quality reporting should, if they are not already, consider a combination of UPC and PHY. These density measures provide PCP-level results, can be easily compared and interpreted by providers and staff, and do not require considerable analyst support. Moreover, considering the recommendation that patients see their PCP at least 75% of the time, this benchmark can only be assessed using a straightforward density measure such as UPC.^13,14 Other measures that emphasize dispersion or sequence information cannot be used to evaluate if the clinic is meeting this benchmark.

Researchers interested in COC should utilize multiple measurement types in order to capture the complexity of COC, which also provides multiple ways of comparing results between studies. A combination of a density measure like UPC and a dispersion measure like BB-COC or MMCI should be sufficient. Studies focussed on residency clinics should consider MMCI over BB-COC, as it may not be skewed by the high number of providers patients may see. While sequence measures are interesting in concept, SECON requires significant analyst support and may only be beneficial among studies interested in patient scheduling and follow-up care. Given the weaknesses of SECON, one of the other 3 measures described in this brief should be used in tandem. Lastly, studies should consider weighting patients’ COC scores by their total number of visits in order to account for differences in the level of health care utilization.

The full complexity of COC cannot be captured by formulas and indices, but they provide an important measure of how consistently patients are interacting with the same provider. This consistency is the foundation upon which the patient–provider relationship is built.

The contents of this manuscript have not been presented or published elsewhere.

Acknowledgments

This study was supported by the Research Services Hub, in the Department of Family Medicine and Community Health, University of Minnesota Medical School.

Conflict of interest

The authors declare they have no conflicts or competing interests.

References

1.

Starfield

B

,

Shi

L

,

Macinko

J.

Contribution of primary care to health systems and health

.

Milbank Q

.

2005

:

83

(

3

):

457

–

502

. doi:10.1111/j.1468-0009.2005.00409.x

2.

Kringos

DS

,

Boerma

WG

,

Hutchinson

A

,

van der Zee

J

,

Groenewegen

PP.

The breadth of primary care: a systematic literature review of its core dimensions

.

BMC Health Serv Res

.

2010

:

10

(

1

):

65

. doi:10.1186/1472-6963-10-65

3.

Nowak

DA

,

Sheikhan

NY

,

Naidu

SC

,

Kuluski

K

,

Upshur

REG.

Why does continuity of care with family doctors matter? review and qualitative synthesis of patient and physician perspectives

.

Can Fam Physician

.

2021

:

67

(

9

):

679

–

688

. doi:10.46747/cfp.6709679

4.

Peccoralo

LA

,

Tackett

S

,

Ward

L

,

Federman

A

,

Helenius

I

,

Christmas

C

,

Thomas

DC.

Resident satisfaction with continuity clinic and career choice in general internal medicine

.

J Gen Intern Med

.

2013

:

28

(

8

):

1020

–

1027

. doi:10.1007/s11606-012-2280-5

5.

Ledford

C

,

Guard

E

,

Phillips

J

,

Morley

C

,

Prunuske

J

,

Wendling

A.

How medical education pathways influence primary care specialty choice

.

Fam Med

.

2022

:

54

(

7

):

512

–

521

. doi:10.22454/FamMed.2022.668498

6.

Baker

R

,

Freeman

GK

,

Haggerty

JL

,

Bankart

MJ

,

Nockels

KH.

Primary medical care continuity and patient mortality: a systematic review

.

Br J Gen Pract

.

2020

:

70

(

698

):

e600

–

e611

. doi:10.3399/bjgp20X712289

7.

Bazemore

A

,

Petterson

S

,

Peterson

LE

,

Bruno

R

,

Chung

Y

,

Phillips

RL.

Higher primary care physician continuity is associated with lower costs and hospitalizations

.

Ann Fam Med

.

2018

:

16

(

6

):

492

–

497

. doi:10.1370/afm.2308

8.

Connolly

MJ

,

Weppner

WG

,

Fortuna

RJ

,

Snyder

ED.

Continuity and health outcomes in resident clinics: a scoping review of the literature

.

Cureus

.

2022

;

14

(

5

):

e25167

. doi:10.7759/cureus.25167

9.

Saultz

JW

,

Albedaiwi

W.

Interpersonal continuity of care and patient satisfaction: a critical review

.

Ann Fam Med

.

2004

:

2

(

5

):

445

–

451

. doi:10.1370/afm.91

10.

Saultz

JW

,

Lochner

J.

Interpersonal continuity of care and care outcomes: a critical review

.

Ann Fam Med

.

2005

:

3

(

2

):

159

–

166

. doi:10.1370/afm.285

11.

Van Walraven

C

,

Oake

N

,

Jennings

A

,

Forster

AJ.

The association between continuity of care and outcomes: a systematic and critical review

.

J Eval Clin Pract

.

2010

:

16

(

5

):

947

–

956

. doi:10.1111/j.1365-2753.2009.01235.x

12.

Yang

Z

,

Ganguli

I

,

Davis

C

,

Dai

M

,

Shuemaker

J

,

Peterson

L

,

Bazemore

A

,

Phillips

R

,

Chung

YK.

Physician- versus practice-level primary care continuity and association with outcomes in Medicare beneficiaries

.

Health Serv Res

.

2022

:

57

(

4

):

914

–

929

. doi:10.1111/1475-6773.13999

13.

2012 VHA Facility Quality and Safety Report

.

Veterans Health Administration, Department of Veterans Affairs

;

2012

.

Google Preview

. http://www.ncbi.nlm.nih.gov/books/NBK532528/

14.

Bodenheimer

T

,

Ghorob

A

,

Willard-Grace

R

,

Grumbach

K.

The 10 building blocks of high-performing primary care

.

Ann Fam Med

.

2014

:

12

(

2

):

166

–

171

. doi:10.1370/afm.1616

15.

Perry

RJ

,

McCall

N

,

Wensky

SG

,

Haber

SG.

Care Continuity in a Patient-Centered Medical Home Setting

.

RTI Press

;

2016

. Accessed

March 2, 2023

Google Preview

16.

Buttorff

C

,

Timbie

JW

,

Lavelle

TA

,

Malsberger

R

,

Kress

,

AM

,

Setodji

CM

,

Kahn

KL

.

Do interventions promoting medical homes in FQHCs improve continuity of care for Medicare beneficiaries

?

J Public Health

.

2021

:

29

(

2

):

255

–

267

. doi:10.1007/s10389-019-01090-4

Crossref

17.

Fortuna

RJ

,

Garfunkel

L

,

Mendoza

MD

,

Ditty

M

,

West

J

,

Nead

K

,

Robbins

BW.

Factors associated with resident continuity in ambulatory training practices

.

J Grad Med Educ

.

2016

:

8

(

4

):

532

–

540

. doi:10.4300/JGME-D-15-00755.1

18.

Walker

J

,

Payne

B

,

Clemans-Taylor

BL

,

Snyder

ED.

Continuity of care in resident outpatient clinics: a scoping review of the literature

.

J Grad Med Educ

.

2018

:

10

(

1

):

16

–

25

. doi:10.4300/JGME-D-17-00256.1

19.

Darden

PM

,

Ector

W

,

Moran

C

,

Quattlebaum

TG.

Comparison of continuity in a resident versus private practice

.

Pediatrics

.

2001

:

108

(

6

):

1263

–

1268

. doi:10.1542/peds.108.6.1263

20.

Barker

I

,

Steventon

A

,

Deeny

SR.

Association between continuity of care in general practice and hospital admissions for ambulatory care sensitive conditions: cross sectional study of routinely collected, person level data

.

BMJ

.

2017

:

356

:

j84

. doi:10.1136/bmj.j84

21.

Kiran

T

,

Green

ME

,

Bai

L

,

Latifovic

L

,

Khan

S

,

Kopp

A

,

Frymire

E

,

Glazier

RH.

Relational continuity, physician payment, and team-based primary care in the Canadian health care system

.

J Am Board Fam Med

.

2023

. doi:10.3122/jabfm.2022.220235R1

22.

Hetlevik

O

,

Gjesdal

S.

Personal continuity of care in Norwegian general practice: a national cross-sectional study

.

Scand J Prim Health Care

.

2012

:

30

(

4

):

214

–

221

. doi:10.3109/02813432.2012.735554

23.

Jee

SH

,

Cabana

MD.

Indices for continuity of care: a systematic review of the literature

.

Med Care Res Rev

.

2006

:

63

(

2

):

158

–

188

. doi:10.1177/1077558705285294

24.

Saultz

JW.

Defining and measuring interpersonal continuity of care

.

Ann Fam Med

.

2003

:

1

(

3

):

134

–

143

. doi:10.1370/afm.23

25.

Bentler

SE

,

Morgan

RO

,

Virnig

BA

,

Wolinsky

FD.

Evaluation of a patient-reported continuity of care model for older adults

.

Qual Life Res

.

2014

:

23

(

1

):

185

–

193

. doi:10.1007/s11136-013-0472-z

26.

Bentler

SE

,

Morgan

RO

,

Virnig

BA

,

Wolinsky

FD.

Do claims-based continuity of care measures reflect the patient perspective

?

Med Care Res Rev

.

2014

:

71

(

2

):

156

–

173

. doi:10.1177/1077558713505909

27.

Rodriguez

HP

,

Marshall

RE

,

Rogers

WH

,

Safran

DG.

Primary care physician visit continuity: a comparison of patient-reported and administratively derived measures

.

J Gen Intern Med

.

2008

:

23

(

9

):

1499

–

1502

. doi:10.1007/s11606-008-0692-z

28.

Pollack

CE

,

Hussey

PS

,

Rudin

RS

,

Fox

DS

,

Lai

J

,

Schneider

EC.

Measuring care continuity: a comparison of claims-based methods

.

Med Care

.

2016

:

54

(

5

):

e30

–

e34

. doi:10.1097/MLR.0000000000000018

29.

Smedby

O

,

Eklund

G

,

Eriksson

EA

,

Smedby

B.

Measures of continuity of care: a register-based correlation study

.

Med Care

.

1986

:

24

(

6

):

511

–

518

.

30.

Breslau

N

,

Reeb

KG.

Continuity of care in a university-based practice

.

J Med Educ

.

1975

:

50

(

10

):

965

–

969

. doi:10.1097/00001888-197510000-00006

31.

Bice

TW

,

Boxerman

SB.

A quantitative measure of continuity of care

.

Med Care

.

1977

:

15

(

4

):

347

–

349

. doi:10.1097/00005650-197704000-00010

32.

Godkin

M

,

Rice

C.

A measure of continuity of care for physicians in practice

.

Fam Med

.

1984

:

16

(

4

):

136

–

140

.

33.

Magill

MK

,

Senf

J.

A new method for measuring continuity of care in family practice residencies

.

J Fam Pract

.

1987

:

24

(

2

):

165

–

168

.