A Meta-Analysis of Interventions to Improve

Chronic Illness Care

Alexander Tsai1 (act2@case.edu), S.C. Morton2, C.M. Mangione3,

E.B. Keeler2

1 Case School of Medicine; 2 RAND Health; 3 David Geffen School of Medicine at UCLA

AcademyHealth Annual Research Meeting, June 7, 2004

The Chronic Care Model

Objective

• Lack of controlled studies of the CCM– But there have been controlled studies of

interventions that incorporate one or more CCM elements

• Using meta analysis, we sought to:– Determine the extent to which CCM-style

interventions improve chronic illness care– Determine whether any specific CCM

elements were essential to improved outcomes

Table 1. Outcomes of Interest

Clinical Outcomes Quality of Life Processes

(Continuous) (Dichotomous) (Continuous) (Dichotomous)

Asthma # ED visits % with at least one ED visit

Quality of life % with long-acting meds

CHF # hospital readmissions

% with at least 1 readmission

Quality of life % with ACE inhibitor

Depression Depression Scale

% depressed /symptomatic

Quality of life or SF-36 MCS

% with antidepressant

Diabetes HbA1c % with HbA1c > 7%

Quality of life % tested for HbA1c level

Data Sources

1. Bibliographies of 23 recently published systematic reviews and meta-analyses: asthma (5), CHF (6), diabetes (7), depression (2), general chronic care (2), information systems (1)

2. MEDLINE 1998-2003

3. Chronic Care Bibliography

Inclusion/Exclusion Criteria

• Inclusion criteria– 1993-2003– Asthma, CHF, depression, diabetes– Controlled (randomized or non-randomized)– Outcomes of Interest

• Exclusion criteria– Not written in English– Non-adult patient population– Insufficient statistics

Data Abstraction

• Data obtained from all relevant associated articles and attributed to the primary citation

• Only 12-month follow-up data recorded if multiple follow-up times assessed

• If missing data, SD conservatively assumed to be 1/4 of the theoretical range for that measure

Statistical Analysis

• Comparisons at follow-up

• Pooled analysis by condition– Hedges’ g (continuous), risk ratio (binary)

• Relative effectiveness of CCM elements– Random-effects meta-regression model

• Funnel plots to detect publication bias

• Cochran’s Q to assess heterogeneity

• Sensitivity analysis for Jadad score ≥3

Table 2. Summary Statistics (N=112)

Element Type DSD SMS DS CIS CR HCO

N 60 80 38 19 4 6

# Elements One Two Three Four Five Six

N 52 33 19 8 0 0

Jadad score Zero One Two Three Four Five

N 19 23 34 36 0 0

Table 3. By ConditionClinical Outcomes Quality of life Processes

[continuous] (lower=better)

[dichotomous] (lower=better)

[continuous] (higher=better)

[dichotomous] (higher=better)

Effect Size RR Effect Size RR

OVERALL -0.23 * 0.84 * 0.11 * 1.19 *

Asthma 0.82 * 0.01 1.61

CHF 0.81 * 0.28 * 1.13 *

Depression -0.25 * 0.83 * 0.18 * 1.28 *

Diabetes -0.19 * 0.92 -0.02 1.10 *

* P<0.05

Table 4. By CCM ElementClinical Outcomes Quality of life Processes

[continuous] (lower=better)

[dichotomous] (lower=better)

[continuous] (higher=better)

[dichotomous] (higher=better)

Effect Size RR Effect Size RR

DSD -0.21 * 0.77 * 0.33 1.16 *

SMS -0.22 * 0.81 * -0.03 1.31 *

DS -0.14 0.87 0.04 1.29 *

CIS -0.06 0.83 -0.28 1.08

* P<0.05

Conclusions

1. Interventions that contained one or more CCM elements improved clinical outcomes and processes of care for four chronic illnesses

2. Effect on quality of life was mixed

3. The specific CCM elements most responsible for the beneficial effects could not be determined

Limitations

• Testing the CCM vs. testing CCM elements– Unable to assess intensity of implementation

• Unexplained heterogeneity in aggregating across conditions and types of interventions

• Conclusions limited to selected outcomes and selected conditions

For additional information:

http://www.rand.org/health/ICICE

E-mail:

act2@case.edu

Standardized effect size-2 -1 0 1

Combined Whitlock (2000)

Weinberger (1995) Tu (1993)

Thompson (1999) Stroebel (2002)

Ridgeway (1999) Piette (2001) Piette (2000) Pieber (1995)

Olivarius (2001) O'Connor (1996)

Meigs (2003) Laffel (1998)

Kinmonth (1998) Keyserling (2002)

Jaber (1996) Hurwitz (1993)

Hoskins (1993) Hirsch (2002)

Glasgow (2003) Glasgow (2000)

De Sonnaville (199 DICET (1994) Brown (2002)

Benjamin (1999) Worrall (1999)

Whooley (2000) Unutzer (2002)

Tutty (2000) Simon (2000)

Rubenstein (2003) Rost (2001)

Rollman (2002) Rabins (2000)

Mynors-Wallis (200 Miranda (2003)

Mann (1998) Llewellyn-Jones (1

Leveille (1998) Katzelnick (2000)

Katon (1999) Katon (1996) Katon (1995)

Hunkeler (2000) Goldberg (1998)

Datto (2003) Coleman (1999) Callahan (1994)

Brown (2000) Blanchard (1995)

Barrett (2001) Banerjee (1996)

Fig 1. Clinical Outcomes (Continuous)

Pooled Effect Size = -0.23 (-0.31, -0.15) favoring intervention

Q=230, df=51, P<0.001

Depression

Diabetes

Relative risk.25 .5 1 2 4

Combined Renders (2001)

Piette (2000) Meigs (2003)

De Sonnaville (199 Williams (1999)

Whooley (2000) Wells (2000)

Unutzer (2002) Tutty (2000)

Simon (2000) Rubenstein (2003)

Rollman (2002) Mynors-Wallis (200

Mann (1998) Llewellyn-Jones (1 Katzelnick (2000)

Katon (1999) Banerjee (1996)

Weinberger (1996) Stewart (1999) Stewart (1998) Serxner (1998)

Schneider (1993) Riegel (2002) Riegel (2000)

Rich (1995) Rich (1993)

Philbin (2000) Naylor (1999)

Laramee (2003) Kasper (2002)

Jaarsma (1999) Hughes (2000) Harrison (2002)

Ekman (1998) Cline (1998)

Capomolla (2002) Yoon (1993)

Heard (1999) Harish (2001) Ghosh (1998) Garrett (1994) Cowie (1997) Bailey (1999)

Fig 2. Clinical Outcomes (Binary)

Pooled RR = 0.84 (0.78, 0.90) favoring intervention

Q=135, df=45, P<0.001

Asthma

CHF

Depression

Diabetes

Standardized effect size-2 -1 0 1

Combined

Piette (2000)

Kinmonth (1998)

Glasgow (2000)

Wells (2000)

Unutzer (2002)

Rubenstein (2003)

Stewart (1999)

Rich (1995)

Philbin (2000)

Kasper (2002)

Jaarsma (1999)

Harrison (2002)

Thoonen (2003)

Premaratne (1999)

Levy (2000)

Lahdensuo (1996)

Kotses (1995)

Knoell (1998)

Kauppinen (1998)

Gallefoss (1999)

De Oliveira (1999)

Cote (1997)

Blixen (2001)

Abdulwadud (1999)

Fig 3. Quality of Life

Pooled Effect Size = 0.11 (0.02, 0.21) favoring intervention

Q=93, df=23, P<0.001

Asthma

CHF

Depression

Diabetes

Relative risk.25 .5 1 2 4

Combined

Stroebel (2002)

Reed (2001)

O'Connor (1996)

Meigs (2003)

McDermott (2001)

Kiefe (2001)

Davidson (2000)

DICET (1994)

Branger (1999)

Worrall (1999)

Wells (2000)

Weatherall (2000)

Unutzer (2002)

Rubenstein (2003)

Rost (2001)

Rollman (2002)

Mann (1998)

Katon (1999)

Dowrick (1995)

Coleman (1999)

Callahan (1994)

Brown (2000)

Bashir (2000)

Aubert (2003)

Weinberger (1996)

Philbin (2000)

Kasper (2002)

Gattis (1999)

Cline (1998)

Akosah (2002)

Gallefoss (1999)

Eccles (2002)

Fig 4. Processes of Care

Pooled RR = 1.19 (1.10, 1.28) favoring intervention

Q=312, df=31, P<0.001

Asthma

CHF

Depression

Diabetes