Table 2

Clusters within the high-risk population

Cluster
1234ANOVA/Kruskal- Wallis/χ2 test
Clustering variables
 Number of emergency hospitalisations over 2008–2011, median (IQR)1 (0–1)‡3 (2–4)*1 (0–1)‡3 (2–4)*KW: <0.000
 Number of non-emergency hospitalisations over 2008–2011, median (IQR)3 (2–5)*3 (2–5)*0 (0–1)*0 (0–1)*KW: <0.000
 Number of outpatient attendances over 2008–2011, median (IQR)24 (16–38)*29 (18–46)*7 (3–13)*10 (5–18)*KW: <0.000
 Number of GP visits over 2008–2011, median (IQR)61 (43–90)*57 (40–86)*55 (35–82)*42 (26–65)*KW: <0.000
Post hoc analysis of other variables
 Number of people1967180718311861
 Predicted proportion with any emergency hospitalisations in 2012 (based on average risk score), %21*38*20*31*AN: <0.000
 Actual proportion with any emergency hospitalisations in 2012, %19‡35‡21‡34‡χ2: <0.000
 Age at end of study period, mean79*67*83*71*AN: <0.000
 Number of long-term conditions, median (IQR)2 (1–3)‡2 (1–3)‡1 (1–2)*1 (1–2)*KW: <0.000
 Number of emergency hospitalisations in 2012, median (IQR)2 (1–3)‡2 (1–3)‡1 (1–2)‡1 (1–2)‡KW: <0.000
 Number of non-emergency hospitalisations in 2012, median (IQR)0 (0–0)‡0 (0–1)‡0 (0–0)*0 (0–1)*KW: <0.000
 Number of outpatient attendances in 2012, median (IQR)0 (0–1)*0 (0–1)*0 (0–0)*0 (0–0)*KW: <0.000
 Number of GP visits in 2012, median (IQR)5 (2–10)*6 (3–11)‡2 (0–4)‡2 (0–5)*KW: <0.000
 Prevalence of acute myocardial infarction, %15*23*10*19*χ2: <0.000
 Prevalence of asthma, %28†2624†25χ2: 0.028
 Prevalence of cancer, %26*22*8*5*χ2: <0.000
 Prevalence of cerebrovascular disease, %9‡15‡10‡18‡χ2: <0.000
 Prevalence of congestive heart failure, %8*13‡5*13‡χ2: <0.000
 Prevalence of COPD, %18†17†13*18†χ2: <0.000
 Prevalence of dementia, %3‡3‡5‡7‡χ2: <0.000
 Prevalence of diabetes, %28‡22‡28‡22‡χ2: <0.000
 Prevalence of HIV/AIDS, %0000χ2: 0.39
 Prevalence of learning disabilities, %0†0†00χ2: 0.032
 Prevalence of liver disease, %11†0‡1†χ2: <0.000
 Prevalence of mental health conditions, %2†3†2†5*χ2: <0.000
 Prevalence of paraplegia, %1‡3‡1‡3‡χ2: <0.000
 Prevalence of peptic ulcer, %4†4†2‡3χ2: <0.000
 Prevalence of peripheral vascular disease, %8*11*4‡6‡χ2: <0.000
 Prevalence of renal disease, %23†23†24†18*χ2: <0.000
 Prevalence of rheumatic disease, %10‡8†6†5‡χ2: <0.000

  • *Significantly different from three other clusters.

  • †Significantly different from one other clusters.

  • ‡Significantly different from two other clusters; all at 0.05/4=0.0125 significance level (Bonferroni adjustment).