For each participant, change from Baseline (Followup score - Baseline score) in Quality of Life at 3 months was assessed using the first item of the Taiwanese version of the World Health Organization Quality of Life Questionnaire (WHOQOL-BREF). The item was rated on a 5-point Likert scale, ranging from 1 to 5. Higher scores indicate better quality of life.

For each patient, change from Baseline (Followup score - Baseline score) in patient's Helping Relationships from Significant Others at 3 months was assessed using the Chinese version of the Helping Relationships from Significant Others Scale (HRSO).The scale consists of 15 items rated on a 7-point Likert scale, with total scores ranging from 15 to 105. Higher scores indicate better support from the significant other.

For each participant, change from Baseline (Followup score - Baseline score) in Dyadic Adjustment at 3 months was assessed using the 7-item Dyadic Adjustment Scale (DAS-7). The first six items are rated on a 6-point scale, while the seventh item is rated on a 7-point scale. The total scores range from 0 to 36, with higher scores indicating better relationship quality.

The control group receives routine education and care.

Total of all reporting groups

All 109 participants completed the baseline measure of Sex. However, the count of sex for significant others or all participants together is not of great interest to our study and could be misleading as the role of the significant other (e.g., the patient's spouse, child, or grandchild) is not taken into account. Therefore, this measure reported here includes patient only.

Race and Ethnicity were not collected from any participant.

Estimated Glomerular Filtration Rate (eGFR) by the IDMS-MDRD Equation

This measure includes patient only.

A patient's stage of chronic kidney disease (CKD) based on eGFR. Criteria: Stage 1 (eGFR 90 or above), Stage 2 (eGFR 60-89), Stage 3a (eGFR 45-59), Stage 3b (eGFR 30-44), Stage 4 (eGFR 15-29), Stage 5 (eGFR less than 15). Higher stages (Stage 3b, Stage 4, and Stage 5) represent more advanced and severe progression of chronic kidney disease, with Stage 5 being the most advanced stage.

This measure includes patient only.

The TTM stages of change in lifestyle modification were assessed using five statements based on the Transtheoretical Model (TTM). Patients and their significant others self-assessed their motivation for lifestyle modification, identifying as being in the "precontemplation," "contemplation," "preparation," "action," or "maintenance" stage.

This measure was reported jointly by the patient and the significant other within each dyad.

Patients' lifestyles were assessed using the Chinese version of the Health Promoting Lifestyle Profile-II (HPLP-II), a validated scale with 52 items rated on a 4-point Likert scale. The total score ranges from 52 to 208, with higher scores indicating better health-promoting behavior.

This measure includes patients only.

Patients' adherence to healthy behaviors over the past month was measured using the Adherence to Healthy Behaviors Scale (AHBS). The scale includes 13 items rated on a 5-point Likert scale, with total scores ranging from 0 to 52. Higher scores indicate better adherence.

This measure includes patient only.

Patients' perceived support from their significant others over the past month was assessed using the Chinese version of the Helping Relationships from Significant Others Scale (HRSO). The scale consists of 15 items rated on a 7-point Likert scale, with total scores ranging from 15 to 105, with higher scores indicating better support.

This measure includes patient only.

The quality of the relationship between the patient and their significant other was assessed using the 7-item Dyadic Adjustment Scale (DAS-7). The first six items are rated on a 6-point scale, while the seventh item is rated on a 7-point scale, with total scores ranging from 0 to 36. Higher scores indicate better relationship quality.

This scale was measured for both patients and their significant others. Specifically, 26 dyads from the intervention group and 29 dyads from the control group completed the baseline assessment for this scale. However, one significant other from the intervention did not complete the baseline assessment for this scale. As a result, 51 (26*2-1) participants from the intervention group and 58 (29*2) participants from the control group were included for the analysis population of this scale.

The Taiwanese version of the World Health Organization Quality of Life Questionnaire (WHOQOL-BREF) was used to assess the quality of life of patients and their significant others over the past two weeks. The first item assessing general quality of life, rated on a 5-point Likert scale (score range: 1 to 5), was reported for this measure. Higher scores indicate better quality of life.

The control group receives routine education and care.

For each patient, the change from Baseline in CKD stage at 3 months was obtained by comparing the CKD stage at baseline and at follow-up, converted into the following three categories: (1) recover (e.g., from Stage 3a [at baseline] to Stage 2 [at follow-up]); (2) stable (e.g., remaining Stage 3a at both baseline and follow-up); and (3) progress (e.g., from Stage 3a [at baseline] to Stage 3b [at follow-up]).

This measure was conducted only on the patient participants.

For each dyad, change from Baseline in TTM stage at 3 months was obtained by comparing the TTM stage of change at baseline and at follow-up, converted into the following three categories: (1) regress (e.g., from Preparation [at baseline] to Contemplation [at follow-up]); (2) maintain (e.g., remaining Action at both baseline and follow-up); and (3) advance (e.g., from Action [at baseline] to Maintanece [at follow-up]).

This measure was reported jointly by the patient and the significant other within each dyad.

For each patient, change from Baseline (Followup score - Baseline score) in patient's Health Promoting Lifestyle at 3 months was assessed using the Chinese version of the Health Promoting Lifestyle Profile-II (HPLP-II), a validated scale with 52 items rated on a 4-point Likert scale. The total scores range from 52 to 208, with higher scores indicate better health-promoting behavior.

This questionnaire was only administrated to the patient participants.

For each participant, change from Baseline (Followup score - Baseline score) in Quality of Life at 3 months was assessed using the first item of the Taiwanese version of the World Health Organization Quality of Life Questionnaire (WHOQOL-BREF). The item was rated on a 5-point Likert scale, ranging from 1 to 5. Higher scores indicate better quality of life.

This scale was measured for both patients and their significant others. Specifically, 26 dyads from the intervention group and 29 dyads from the control group completed the baseline assessment for this scale. However, one significant other from the intervention did not complete the baseline assessment for this scale. As a result, 51 (26*2-1) participants from the intervention group and 58 (29*2) participants from the control group were included for the analysis population of this scale.

For each patient, change from Baseline (Followup score - Baseline score) in patient's adherence to healthy behaviors was measured using the Adherence to Healthy Behaviors Scale (AHBS). The scale includes 13 items rated on a 5-point Likert scale, with total scores ranging from 0 to 52. Higher scores indicate better adherence.

This questionnaire was only administrated to the patient participants.

For each patient, change from Baseline (Followup score - Baseline score) in patient's Helping Relationships from Significant Others at 3 months was assessed using the Chinese version of the Helping Relationships from Significant Others Scale (HRSO).The scale consists of 15 items rated on a 7-point Likert scale, with total scores ranging from 15 to 105. Higher scores indicate better support from the significant other.

This questionnaire was only administrated to the patient participants.

For each participant, change from Baseline (Followup score - Baseline score) in Dyadic Adjustment at 3 months was assessed using the 7-item Dyadic Adjustment Scale (DAS-7). The first six items are rated on a 6-point scale, while the seventh item is rated on a 7-point scale. The total scores range from 0 to 36, with higher scores indicating better relationship quality.

This scale was measured for both patients and their significant others. Specifically, 26 dyads from the intervention group and 29 dyads from the control group completed the baseline assessment for this scale. However, one significant other from the intervention did not complete the baseline assessment for this scale. As a result, 51 (26*2-1) participants from the intervention group and 58 (29*2) participants from the control group were included for the analysis population of this scale.

The control group receives routine education and care.