Table 2 Details of the studies included in the review

Bame et al, 1993 U.S. [12]

1230 HD

57

Not stated

47%

Multiple logistic regression

Age*, income*, gender, ethnicity, marital status, education

Not assessed

Not assessed

Serum phosphorus

>6 mg/dl

50%

Betts & Crotty, 1988 U.S.[42]

46 HD

Not stated

Not stated

33%

Correlations

Age, education

Time on dialysis

Response to illness

Serum phosphorus

> 5 mg/dl

74%

Blanchard et al, 1990 U.S.[38]

40 HD 40 PD

50

Not stated

48%

Correlations

Gender

Time on dialysis

Not assessed

Self report

Reporting ever missing a dose

28%

Boyer et al, 1990 U.S.[13]

60 HD

Not stated

Not stated

71%

Correlations, multiple regression

Age*, marital status*, gender, ethnicity, income, education

Time on dialysis

Social support*

Serum phosphorus

Not dichotomised

Not stated

Christensen et al, 1994 U.S.[14]

52 HD 34 PD

49

73

53%

Hierarchical regression

Age**, gender, marital status, education

Diabetic status, time on dialysis, transplant history, type of dialysis

Information vigilance, active coping

Serum phosphorus

Not dichotomised

Not stated

Christensen et al, 1995 U.S.[15]

72 HD or PD

46

73

54%

Correlations, stepwise regression

Age*, education

Time on dialysis, transplant history

Neuroticism, extraversion, openness to experience, agreeableness, conscientiousness*

Serum phosphorus

Not dichotomised

Not stated

Christensen et al, 1996a U.S.[44]

52 HD

59

62

59%

Regression

Age, education, gender

Diabetic status, time on dialysis

Neuroticism, private body consciousness, illness related physical impairment

Serum phosphorus

Not dichotomised

Not stated

Christensen et al, 1996b U.S. [16]

67 HD 14 PD

55

70

49%

Regression

Age **, education, gender

Diabetic status*, type of dialysis, time on dialysis

Perceived health competence*, health locus of control

Serum phosphorus

Not dichotomised

Not stated

Christensen et al, 1997a U.S.[33]

51 HD

57

51

59%

Correlation, hierarchical regression

Age, education, gender

Diabetic status, time on dialysis

Monitoring attentional style, trait anxiety, internal health locus of control, control appraisal, avoidant coping

Serum phosphorus

Not dichotomised

Not stated

Christensen et al, 1997b U.S.[43]

48 HD

56

65

54%

Correlations, hierarchical regression

Age, education, gender

Diabetic status, time on dialysis

Cynical hostility*, health locus of control

Serum phosphorus

Not dichotomised

Not stated

Cummings et al, 1982 U.S.[22]

116 HD

55

29

54%

Correlations, regression

Age*, gender, income, education

Time on dialysis, transplant history, regimen complexity*

Susceptibility, severity, benefits*⁺, barriers⁺, knowledge of purpose of regimen*, social support (family and friends), support from medical staff⁺, family problems⁺

Serum phosphorus Self report

>5.5 mg/dl

70% (based on serum phosphorus)

Curtin et al, 1999 U.S.[49]

135 HD

63

Not stated

47%

Chi-square

Ethnicity^###, age, gender, employment status, education

Cause of renal failure, no. comorbidities, time on dialysis

Not assessed

Electronic monitoring (used in analysis)

Pill count

Self report

Overdosing/underdosing/missing more than 20% prescribed doses

73% (based on electronic monitoring)

Eitel et al, 1998 U.S.[27]

40 HD 45 PD

55

40

61%

Correlations

Not assessed

Not assessed

Efficacy expectations**, effort attributions, self control

Serum phosphorus (used in analysis)

Self report

Staff ratings

Not dichotomised

Not stated

Gago et al, 2000 Spain[35]

121 HD

63

37

56%

T-tests

Gender, age, living arrangements

Cause of ESRD, time on dialysis

Knowledge

Not clear

Not clear

46%

Hilbert, 1985 U.S.[29]

26 HD

47

54

35%

Correlations, ANOVA

Age, income, education, social class, religion, gender, significant other

No. times hospitalised, time on dialysis⁺

Directive guidance social support⁺, affection social support

Composite self report scale – adherence to medication, fluid and diet (used in analysis) Serum phosphorus

Not dichotomised

Not stated

Horne et al, 2001 U.K.[17]

47 HD

49

53

49%

Correlations

Age⁺, gender, education

Duration of ESRD, time on dialysis, no. prescribed medicines

Beliefs about medication (concerns ⁺⁺, perceived need, harm, overuse)

Self report

Those who reported sometimes, often or very often deliberately missing a dose of their medication.

26%

Leggat et al, 1998 U.S.[18]

6251 HD

58

54

50%

Logistic regression

Age***, ethnicity*, smoker*, gender, education, living arrangements

Time on dialysis, diabetic status, transplant history

Not assessed

Serum phosphorus

>7.5 mg/dl

22%

Lin & Liang, 1997 China[39]

86 HD

55

42

45%

Correlations

Not assessed

Not assessed

Health locus of control^+++, **

3 composite measures: Lab reports (including serum phosphorus)

Self report – fluid, diet and medication adherence

Nurses' assessment – fluid, diet and medication adherence

>4.59 mg/dl

61% (based on serum phosphorus)

Moran et al, 1997 U.S.[45]

56 HD

57

46

64%

Regression

Age, gender, education

Time on dialysis, diabetic status, transplant history**

Social support, conscientiousness

Serum phosphorus

Not dichotomised

Not stated

Morduchowicz et al, 1993 Israel[46]

50 HD

56

66

60%

Multivariate and stepwise regression

Education ***, ethnicity*, gender, age, place of birth, religious observance, marital status, no. children, whether accompanied to session, economic status, living arrangements

Previous PD dialysis, time on dialysis

Not assessed

Serum phosphorus

Not dichotomised

Not stated

O'Brien, 1980 U.S.[28]

63 HD

Not stated

Not stated

54%

ANOVA, correlations, regression

Age, gender, marital status⁺⁺, ethnicity, education, occupation, type of household

Time on dialysis

Significant others' expectations regarding adherence⁺⁺⁺

Composite self report scale – dialysis attendance, diet, fluid and medication

Not stated

Not stated

Reiss et al, 1986 U.S.[47]

23 HD

48

8

57%

Correlations

Family income, marital status, years married, family size, education

Not assessed

Problem solving (coordination and closure), family intelligence

Serum phosphorus

Not dichotomised

Not stated

Schlebusch & Levin, 1982 South Africa[34]

25 HD or PD

38

Not stated

48%

Mann-Whitney test

Not assessed

Organicity (cortical dysfunction)^$

Intelligence, personality^$$

Composite staff rating – including adherence to medication and diet

Not stated

44%

Schneider, 1992 U.S.[19]

137 HD

51

26

54%

Multiple regression

Age***, gender, ethnicity, education

Time on dialysis, frequency of physician contact

Health locus of control***

Serum phosphorus

Not dichotomized

Not stated

Sherwood, 1983 U.S.[30]

55 HD

46

48

66%

Correlations

Not assessed

Not assessed

Family understanding, family organisation*, supportive family**,⁺⁺⁺

Serum phosphorus Composite self-report measure – diet, fluid and medication

Not stated

Not stated

Stamatakis et al, 1997 U.S.[20]

17 HD

4 PD

53

Not stated

48%

Anova, chi-square, multiple regression

Age*, gender, ethnicity education, occupation, marital status

Type of dialysis, cause of ESRD, transplant history

Knowledge*

Serum phosphorus Self report

Not stated

Not stated

Steidl et al, 1980 U.S.[31]

22 HD

1 PD

43

22

57%

Correlations

Not assessed

Medical assessment

Family functioning^$$$

Composite staff assessment – dialysis attendance/medication and diet adherence

Not stated

Not stated

Takaki et al, 2003 Japan[21]

484 HD

60

98

66%

Correlations, multiple regression

Age***, gender

Time on dialysis***

Not assessed

Serum phosphorus

Not dichotomised

Not stated

Tomasello et al. 2004 U.S.[3]

129 HD 59 PD

60

46

Not stated

ANOVA

Age

Time on dialysis, diabetic status, tablet burden*

Not assessed

Self report

Serum phosphorus

Reporting taking less than 80% medication as prescribed

>5.5 mg/dl

38% (based on self report) 51% (based on serum phosphorus)

Tracy et al, 1987 U.S.[40]

15 HD

52

0 (starting dialysis)

67%

Correlations, ANOVA

Not assessed

Not assessed

Personality*, depression*, family environment

Composite measure – serum phosphorus and interdialytic weight

Not stated

Not stated

Vives et al, 1999 Spain[41]

31 HD

63

35

74%

Mann Whitney, Wilcoxon, T-test

Age, gender

Duration of treatment

Health locus of control

Composite score based on serum phosphorus, serum potassium and interdialytic weight

>6.01 mg/dl

Not stated

Weed-Collins & Hogan, 1989 U.S.[26]

30 HD

Not stated

Not stated

43%

Correlations

Not assessed

Not assessed

Knowledge of phosphate binders, susceptibility, severity, benefits, barriers*

Serum phosphorus

>5.5 mg/dl

64%

Wenerowicz et al, 1978 U.S.[37]

19 HD

36

7

68%

Chi-square, t-test

Not assessed

Not assessed

Health locus of control *

Serum phosphorus

>4.5 mg/dl

68%

Wiebe & Christensen, 1997 U.S.[48]

70 HD

56

141

60%

Stepwise, hierarchical regression

Age, gender, education, marital status

Diabetic status, time on dialysis

Conscientiousness, susceptibility, severity, benefits, barriers

Serum phosphorus

Not dichotomised

Not stated