**3.4 Perception of health-related quality of life in terms of age**

In both interventions, the physical component of HRQOL was more affected in patients older than 65 than in younger individuals. This was constant throughout the study. In the RPP group, these differences at the start of the study and one year later were statistically significant for PCS1 (p=0.001, ES start=0.08; p<0.001, ES year=0.06), for the physical functioning domain (p=0.001, ES start=0.30; p<0.001, ES year=0.03) and for bodily pain (p=0.009, ES start=0.02; p=0.025, ES year=0.10). In CT, however, the differences found between the age groups at the start were in PCS1 (p=0.025, ES start=0.44), in the physical functioning domain (p=0.001, ES start=0.61) and in role-physical (p=0.022, ES start=0.43). One year later, differences were found in physical functioning (p=0.022, ES year=0.57) and general health (p=0.021, ES year=0.45). See Table 4.

After analyzing changes within each group and for each age group, it was observed that the RPP patients who were 65 and older showed significant changes in physical functioning (p=0.006, ES=0.30) after one year. Patients younger than 65 showed no changes after this time. In CT, patients younger than 65 showed significant changes in MCS1 (p=0.044, ES=0.34) and in the social functioning domain (p=0.003, ES=0.53). Patients who were 65 and older showed changes after one year in physical functioning (p=0.050, ES=0.15), general health (p=0.001, ES=0.35) and vitality (p=0.044, ES=0.20) See Table 4.

## **3.5 Health-related quality of life adjusted for previous measurements, age, and gender**

After adjusting the second measurement's raw HRQOL score (See Table 2) for the initial HRQOL score, significant differences were found between the RPP and the CT groups in the following domains: general health (a difference of 5.2 points favoring the RPP) and change in health (the difference of 5.9 points continues to favor the RPP). After adjusting it for gender, differences were found in PCS1 (a difference of 7.7 points favoring the RPP) and vitality (a difference of 6.9 points favoring the RPP). When the score was adjusted for age, differences were then found in physical functioning (a difference of 7.2 points favoring CT). No significant differences were found upon adjusting HRQOL for stage, hypertension, diabetes, and dyslipidemia (See Table 5).

Health-Related Quality of Life in Chronic Renal Predialysis

**Mean adjusted for initial HRQOL** 

**Domains and summary scores** 

CHANGES IN

**4. Discussion** 

MCS1: Mental health summary score.

variable. P value: \* p<0.05 \*\*p<0.01.

quality of life, gender, and age. Medellín, 2007-2008.

participate (1 due to disease), 4 couldn't be contacted, and 6 had died.

(Chandban et al., 2003; Fukuhara et al., 2007; Valdebarrano et al., 2001).

**3.6 Reasons for not participating in the study** 

Patients Exposed to a Prevention Program – Medellín, 2007-2008 439

PCS1: 58.2 54.9 58.7\*\* 51.0\*\* 56.0 57.1 Physical Functioning 65.3 64.9 65.5 59.8 61.5\* 68.7\* Role-Physical 66.7 59.4 66.2 56.1 64.3 61.7 Bodily Pain 65.3 64.0 64.8 60.0 63.6 65.6 General Health 58.0\* 52.8\* 57.6 52.6 56.6 54.2 MCS1: 70.5 68.6 69.2 66.6 69.2 69.9 Mental Health 68.7 69.1 67.9 67.2 67.7 70.2 Role-Emotional 72.5 68.6 70.7 65.1 69.2 71.9 Social Functioning 78.0 73.8 77.2 72.1 76.3 75.6 Vitality 65.0 61.8 64.6\*\* 57.7\*\* 63.5 63.3

HEALTH 68.5\* 62.6\* 68.5 63.0 67.2 64.0 RPP: Renal Protection Program. CT: Conventional treatment PCS1: Physical health summary score.

The underlined values correspond to significant difference by intervention type and by adjustment

Table 5. Distribution of health-related quality of life scores in patients with chronic renal failure in predialysis after one year of treatment. Scores are adjusted for initial health-related

The reasons for the unreachability of the remaining 118 patients during the first measurement were: wrong phone number = 43 (40% RPP), occupation = 33 (45% RPP), being out of geographical reach = 17 (35% RPP), and exclusion criteria = 14 (57% RPP). Only 11 patients (36% RPP) were excluded due to concomitant disease or death, which is associated with a decrease in HRQOL. One year later, of the missing RPP patients: 6 refused to participate (2 due to disease), 6 couldn't be contacted, and 3 had died. In CT: 5 refused to

This is the first report in Colombia to provide an account of the factors affecting HRQOL in patients with mild to moderate renal impairment. It is also the first to point out the advantages that a renal protection program may have over conventional treatment regarding its impact on patient HRQOL. This study's results are presented to comply with the demands that appear in international literature regarding the need to determine the impact on HRQOL in early stages of renal impairment (Chandban et al., 2003; Perlman et al., 2005) and to insist that current interventions must emphasize the preservation of renal functioning in order to decrease the negative impact of kidney failure on HRQOL

**Mean adjusted for gender** 

**RPP CT: RPP CT: RPP CT:** 

**Mean adjusted for age** 


RPP: Renal Protection Program. CT: Conventional treatment PCS1: Physical health summary score. MCS1: Mental health summary score. SD: Standard deviation

Table 4. Distribution of HRQOL scores, by age, in patients with chronic renal failure in predialysis before and after an intervention. Medellín, 2007-2008.

PCS1: 53.3 (28.0) 68.9 (26.8) 0.001 51.0 (27.1) 67.2 (25.9) <0.001 Physical Functioning 62.7 (26.1) 77.8 (26.9) 0.001 53.8 (30.7) 78.5 (24.9) <0.001 Role-Physical 57.9 (42.5) 66.3 (40.1) 0.217 60.2 (43.8) 72.9 (40.0) 0.067 Bodily Pain 60.7 (29.5) 73.0 (26.4) 0.009 60.0 (30.6) 70.4 (24.7) 0.025 General Health 56.0 (24.3) 61.7 (22.7) 0.140 56.6 (24.9) 58.6 (22.0) 0.613

MCS1: 70.7 (32.9) 63.4 (33.2) 0.178 68.5 (31.3) 70.2 (23.2) 0.708 Mental Health 69.5 (29.1) 69.8 (24.3) 0.945 67.5 (28.2) 68.6 (20.2) 0.793 Role-Emotional 67.0 (42.7) 62.4 (43.7) 0.518 64.6 (43.7) 77.7 (36.7) 0.051 Social Functioning 76.9 (30.3) 75.7 (27.9) 0.809 73.7 (29.2) 81.2 (23.2) 0.085 Vitality 66.2 (26.8) 68.7 (27.3) 0.576 61.2 (26.5) 68.7 (22.7) 0.068

HEALTH 62.4 (23.1) 70.0 (24.2) 0.052 61.3 (24.3) 76.1 (19.5) <0.001

PCS1: 55.7 (27.6) 67.9 (25.8) 0.025 51.9 (28.3) 62.2 (29.0) 0.068 Physical Functioning 65.2 (27.0) 80.5 (20.9) 0.001 60.5 (31.8) 77.4 (24.8) 0.002 Role-Physical 59.2 (43.8) 77.3 (37.2) 0.022 58.3 (45.2) 64.4 (46.8) 0.498 Bodily Pain 66.7 (28.1) 71.5 (25.1) 0.377 64.8 (28.5) 62.2 (31.6) 0.648 General Health 59.2 (22.8) 64.2 (21.2) 0.262 50.4 (25.7) 62.3 (25.3) 0.021

MCS1: 73.8 (28.9) 79.6 (24.8) 0.302 69.9 (27.0) 69.0 (28.9) 0.875 Mental Health 71.8 (24.5) 78.3 (20.9) 0.167 69.5 (24.3) 70.7 (22.1) 0.811 Role-Emotional 73.4 (39.1) 84.7 (27.9) 0.068 69.0 (41.4) 74.1 (37.1) 0.520 Social Functioning 79.1 (28.1) 87.1 (22.0) 0.136 74.8 (29.0) 73.7 (27.0) 0.851 Vitality 66.0 (24.9) 73.8 (23.0) 0.110 60.7 (26.8) 65.8 (24.6) 0.325

HEALTH 64.3 (21.0) 71.5 (20.6) 0.084 61.4 (23.2) 66.7 (21.6) 0.249

RPP: Renal Protection Program. CT: Conventional treatment PCS1: Physical health summary score.

Table 4. Distribution of HRQOL scores, by age, in patients with chronic renal failure in

Younger

**Initial 1 year** 

Mean (SD) Mean (SD) P value Mean (SD) Mean (SD) P value

older

Younger

than 65 t-Student

than 65 t-Student 65 and

**Domains and Summary Scores** 

**RPP** 

CHANGES IN

CHANGES IN

 **CT:**  65 and older

MCS1: Mental health summary score. SD: Standard deviation

predialysis before and after an intervention. Medellín, 2007-2008.


RPP: Renal Protection Program. CT: Conventional treatment PCS1: Physical health summary score. MCS1: Mental health summary score.

The underlined values correspond to significant difference by intervention type and by adjustment variable. P value: \* p<0.05 \*\*p<0.01.

Table 5. Distribution of health-related quality of life scores in patients with chronic renal failure in predialysis after one year of treatment. Scores are adjusted for initial health-related quality of life, gender, and age. Medellín, 2007-2008.
