All patients in this study received regular nephrology care at National Cheng Kung University Hospital. Nephrologists conducted routine examinations and provided diagnoses based on test results. The patient's condition (e.g., changes in kidney function), treatment plan, prognosis, and risks were explained to both the patient and family members. The treatment plan included medication, monitoring blood pressure, dietary and exercise at home, and consultations with the Health Education Center for kidney care or nutrition advice.

For each patient, change from Baseline in TTM stage at 6 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 Maintenance [at follow-up]).

For each patient, change from Baseline (Followup score - Baseline score) in patient's Health Promoting Lifestyle at 6 months was assessed using the Health Promoting Lifestyle Profile-II Chinese version Revised (HPLP-IICR), a validated scale with 30 items rated on a 4-point Likert scale. The total scores range from 30 to 120, with higher scores indicate better health-promoting lifestyle.

For each participant, change from Baseline (Followup score - Baseline score) in Dyadic Adjustment at 6 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.

All study participants received regular checkups and treatments at the nephrology clinics of National Cheng Kung University Hospital. Nephrologists diagnosed and explained disease progression, treatment plans, prognosis, and risks based on clinical assessments. Care plans included medication adherence, home blood pressure monitoring, dietary adjustments, and regular physical activity. Participants also received nephrology nursing or nutritional counseling through the hospital's Health Education Center.

Total of all reporting groups

All 208 participants completed the baseline measure of Sex. However, the count of sex for 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, we report the count of sex for patient and significant other separately.

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

This measure includes patient only. All 104 patients had baseline eGFR data available. One physiologically implausible value (195.82) from a patient in the intervention group was excluded, leaving 103 datapoints for this measure.

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. All 104 patients had baseline CKD Stage data available.

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

This measure includes patient only. All 104 patients had baseline TTM Stage data available.

Patients' lifestyles were assessed using the Health Promoting Lifestyle Profile-II Chinese Revised (HPLP-IICR), a validated scale with 30 items rated on a 4-point Likert scale. The total score ranges from 30 to 120, with higher scores indicating better health-promoting lifestyle.

This measure includes patient only. All 104 patients had baseline HPLP-IICR data available.

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.

All 208 participants completed the baseline measure of DAS-7. We report the score distribution for patient and significant other separately.

Race and Ethnicity were not collected from any participant.

All study participants received regular checkups and treatments at the nephrology clinics of National Cheng Kung University Hospital. Nephrologists diagnosed and explained disease progression, treatment plans, prognosis, and risks based on clinical assessments. Care plans included medication adherence, home blood pressure monitoring, dietary adjustments, and regular physical activity. Participants also received nephrology nursing or nutritional counseling through the hospital's Health Education Center.

For each patient, change from Baseline in CKD stage at 6 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]).

The test of CKD Stage was conducted only on patient participants. For follow-up, 50 patients from the intervention and 43 patients from the control group completed the CKD Stage measure.

For each patient, change from Baseline in TTM stage at 6 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 Maintenance [at follow-up]).

The test of TTM Stage was conducted only on patient participants. For follow-up, 51 patients from the intervention and 44 patients from the control group completed the TTM Stage measure.

For each patient, change from Baseline (Followup score - Baseline score) in patient's Health Promoting Lifestyle at 6 months was assessed using the Health Promoting Lifestyle Profile-II Chinese version Revised (HPLP-IICR), a validated scale with 30 items rated on a 4-point Likert scale. The total scores range from 30 to 120, with higher scores indicate better health-promoting lifestyle.

This measure was conducted only on patient participants. For follow-up, 51 patients from the intervention and 44 patients from the control group completed the HPLP-IICR measure.

For each participant, change from Baseline (Followup score - Baseline score) in Dyadic Adjustment at 6 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.

For follow-up, 102 participants (51 patients + 51 significant others) from the intervention and 88 participants (44 patients and 44 significant others) from the control group completed the DAS-7 measure.

All study participants received regular checkups and treatments at the nephrology clinics of National Cheng Kung University Hospital. Nephrologists diagnosed and explained disease progression, treatment plans, prognosis, and risks based on clinical assessments. Care plans included medication adherence, home blood pressure monitoring, dietary adjustments, and regular physical activity. Participants also received nephrology nursing or nutritional counseling through the hospital's Health Education Center.