Table 4

Effect estimates of individual-level comorbidity, practice-level and area-level variables on the enrolment in the Disease Management Programme for coronary heart disease obtained from cross-classified multilevel logistic regression models

Measures of association/fixed effects—OR (95%CI)
 M0M1M2M3M4
Individual-level variables
Education (Ref. I, lowest)
 II1.14(0.71 to 1.82)1.14(0.71 to 1.82)1.17(0.73 to 1.87)1.18(0.74 to 1.89)
 III (highest)1.16(0.75 to 1.82)1.16(0.75 to 1.82)1.18(0.76 to 1.84)1.2(0.77 to 1.87)
Sociodemographics
Age group (Ref: 55–64)
 65–741.43(0.91 to 2.25)1.43(0.91 to 2.25)1.44(0.92 to 2.27)1.46(0.93 to 2.30)
 75–841.17(0.73 to 1.88)1.17(0.73 to 1.88)1.18(0.74 to 1.89)1.18(0.74 to 1.89)
 Male (vs female)2.19(1.59 to 3.01)2.19(1.59 to 3.01)2.17(1.58 to 2.98)2.16(1.57 to 2.98)
Comorbidities
 CIRS-G—severity index*1.51(1.09 to 2.11)1.52(1.09 to 2.11)1.51(1.08 to 2.10)1.52(1.09 to 2.12)
Contextual variables
Practice-level
 Male general practitioner (vs female)0.98(0.65 to 1.47)0.98(0.66 to 1.47)1.02(0.68 to 1.54)
Area level
Regional deprivation (Ref.:T1—least deprived)†
 T20.68(0.41 to 1.15)0.70(0.42 to 1.14)
 T3 (most deprived)0.81(0.48 to 1.35)0.92(0.56 to 1.51)
 Degree of urbanisation (Ref: rural)
 Urban cluster0.83(0.55 to 1.25)
 High-density cluster0.56(0.31 to 1.01)
 Intercept0.48 (0.39 to 0.58)0.11(0.05 to 0.24)0.11(0.05 to 0.24)0.14(0.06 to 0.33)0.15(0.06 to 0.37)
Measures of variation/random effects
 Practice-variance0.330.320.320.30.35
 MOR-Practice1.741.721.721.691.75
 PCV (%) Practice−3.0+0.0++−6.3++9.4++
 Municipality-variance0.080.070.070.050.0
 MOR-Municipality1.31.291.291.241.00
 PCV (%) Municipality–12.5+0.0++–28.6++–100++
Model fit and sample size
 Wald-χ2 (df)14.87 (2)‡33.17 (6)33.18 (7)35.35 (9)39.2 (11)
 Model-sig. (p value)0.0006<0.0001<0.00010.0001<0.0001
 N10001000100010001000
 Practice N319319319319319
  • Outcome in all models: Enrolment in the disease management programme for coronary heart disease (Yes vs No). M0: Null model without predictors. M1: Final model with individual-level covariables. M2: Extension of M1 additionally adjusting for the practice-level variable ‘sex of general practitioner’. M3: Extension of M2 with the area-level variable ‘Regional deprivation’. M4: Extension of M3 additionally adjusted for the area-level variable ‘Degree of urbanisation’. MOR: Median OR. PCV: proportional change in variance. PCV+: Compares the change in variance between M1 and M0 on municipality-level/practice-level (reference is the M0 variance on municipality-level/practice-level). PCV++: compares the change in variance on municipality-level/practice-level between the models with contextual variables (M2–M4) and the final model containing individual variables (M1), respectively (reference is the M1 variance on municipality-level/practice-level).

  • *Cumulative Illness Rating Scale (CIRS)—severity index: The OR shows the effect on the propensity of enrolment of a one unit difference in CIRS-severity index, comparing patients with a higher index with patients with a lower index.

  • †Regional deprivation tertiles (T1–T3) refer to the deprivation of the patient-residential area.

  • ‡Test statistic of a likelihood-ratio test, testing the fit of the null model against a single-level logistic regression model.

  • Bold figures indicate ORs that are significantly different from 1.