Compliance in Hemodialysis Patients: Unanticipated Monitoring of Biochemical Indices

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1 Original Paper Blood Purif 1998;16: Accepted: September 23, 1998 Mustafa Arici Bülent Altun Celalettin Usalan Sükrü Ulusoy Yunus Erdem Ünal Yasavul Çetin Turgan Sali Çaglar School of Medicine, Department of Internal Medicine, Division of Nephrology and Hemodialysis Center, Hacettepe University, Ankara, Turkey OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO Key Words Compliance Hemodialysis Biochemical measures Compliance in Hemodialysis Patients: Unanticipated Monitoring of Biochemical Indices OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO Abstract Compliance with the prescribed medical regimen is a critical factor for the continued well-being of hemodialysis patients. As compliance is a multifactorial problem, numerous approaches have been utilized to quantify the compliance of hemodialysis patients. In the present study, we have attempted to examine whether unanticipated control of biochemical indices might predict the compliance status of hemodialysis patients. We compared unanticipated mid-month values of blood urea nitrogen (BUN), serum potassium (K) and phosphate (PO 4 ) values of 54 maintenance hemodialysis patients with the scheduled, regular first- measurements during a 6-month study period. The interdialytic weight gain (IWG) levels of the corresponding s were also compared. Mid-month analysis revealed a significant deviation in the compliance status of the study population as BUN, serum K and IWGs were concerned (p! 0.05). The mid-month serum PO 4 levels were also higher but the difference was not significant (p! 0.05). In conclusion, the differences observed in biochemical indices upon change of test request timing were distinctive. It suggests that unanticipated control of biochemical indices might contribute to the actual assessment of compliance in hemodialysis patients. OOOOOOOOOOOOOOOOO ABC Fax karger@karger.ch S. Karger AG, Basel /98/ $17.50/0 Accessible online at: Yunus Erdem, MD Hacettepe Hastanesi, Nefroloji Bolumu TR Sihhiye/Ankara, (Turkey) Tel , Fax hunephro@superonline.com

2 Introduction Few chronic treatment plans are as complex and difficult as those prescribed for chronic hemodialysis (HD) patients. The frequency and duration of HD, alterations in life-style, physical and psychosocial deprivations, multiple medication needs, episodic access procedures and various other testing and hospitalization requirements are components of every patient s treatment regimen. Hence, successful treatment of a patient in the HD setting requires not only a mathematically adequate dialysis but the appropriate cooperation of the patient in that he has to maintain a strict diet, control fluid intake and comply to medication instructions [1 3]. As compliance is a multifaceted problem, numerous approaches have been utilized in order to quantify the noncompliance of HD patients with dietary and medication prescriptions [4]. The commonest sources of data for adherence to medications and dietary restrictions are sequential values of biochemical indices [5] which have direct implications for health outcome. The frequently used measures are interdialytic weight gain (IWG), as an index of compliance for fluid intake, predialysis serum potassium (K) and blood urea nitrogen (BUN) as measures of dietary compliance and serum phosphate (PO 4 ) as a parameter for medication intake [6, 7]. These parameters are commonly considered to be more reliable and less biased than other measures of compliance such as staff or patient self-reports [8, 9]. Though test request patterns might differ from one center to another [10], the majority of HD centers obtain regular monthly clinical chemistry tests for patients on maintenance treatment [11]. As patients were accustomed to be monitored on a regular basis, the shift in the test request time might distinguish the variations in compliance behavior. In the present study, we have attempted to examine whether unanticipated control of biochemical indices and IWG, instead of the values obtained on a regular basis, might contribute to the assessment of compliance status of chronic HD patients. Patients and Methods The study was conducted in Hacettepe University Outpatient Dialysis Center. All patients, except those with a daily urine volume of more than 100 ml, with a known psychiatric disorder, hospitalized for any reason and receiving a transplant during the study period, were included in the study. A total of 54 patients was qualified for the study. The sociodemographic data including age, sex, and duration of dialysis treatment were obtained from medical chart reviews. All patients were hemodialyzed for 5 h, three times ly, using Cuprophan hollow-fiber dialyzers and a dialysate K content of 2 meq/l. Blood flow was usually maintained at 250 ml/min and dialysate flow was 500 ml/min. The delivered dose of dialysis was calculated monthly according to Daugirdas single-pool Kt/V model [12]. Serum albumin values were recorded monthly for assessing patients nutritional status. All patients were on calcium carbonate as phosphate binder. In the center, a multiple-test laboratory panel (including BUN, creatinine, electrolytes, calcium, phosphorus, liver enzymes, albumin and lipid profile) and complete blood count are obtained in the first of each month before a mid- dialysis session. Nutritional assessment is also performed on a monthly basis and patients receive monthly dietary advice. The IWG, however, is controlled in each session and managed appropriately. The data related to iron status, parathyroid hormone levels and hepatitis surveillance tests are also assessed periodically in the first of each month with regular intervals. An attending nephrologist evaluates the predialysis laboratory values and makes recommendations related to overall health status, fluid and dietary intake and medication usage in the first of each month. As measures of compliance, predialysis serum K, PO 4, BUN and IWGs were analyzed. All measurements were done just before initiation of a mid- dialysis session. Instead of defining categories of compliance as low, moderate or high, we used laboratory parameters as continuous ordinal variables 276 Blood Purif 1998;16: Arici/Altun/Usalan/Ulusoy/Erdem/ Yasavul/Turgan/Çaglar

3 [1, 6]. Compliance data were calculated from the monthly laboratory test results of the consecutive 6 months (the values were summed and divided for average values) and compared with the unexpected laboratory assessment performed in the mid-month of second and fifth months of the study period (the average of two values was used). The IWGs were estimated as the increase in weight gain between the end of the first and beginning of the second ly dialysis in the first of each month and compared with IWGs observed during unanticipated laboratory assessment period. Statistical Analysis Data were expressed as mean B SD. Statistical analysis was performed using the paired-samples t test. The relationship between variables was analyzed by Spearman correlation coefficients. p! 0.05 was considered statistically significant. The data were analyzed using SPSS v 6.0 for Windows (SPSS Inc.). the first of each month (1,608 B 609 g, p! 0.05). The mean arterial pressure values were also higher in mid-month period although the difference was not statistically significant. The serum PO 4 levels were increased in the mid-month analysis (5.33 B 1.67 versus 4.96 B 1.52 mg/dl); however, the difference was not statistically significant (p ) (fig. 1). A moderate positive correlation between age of the patients and the difference in the serum PO 4 values (r = 0.30, p! 0.05) was observed. No other significant correlation was present between study variables and the sociodemographic characteristics of the patients. Results The 54 patients included 35 males and 21 females. The mean age of the patients at time of the study was 40 B 12 years (range 18 70). Mean time on dialysis was 91 B 50 months (range 6 233). During the 6-month study period, the monthly Kt/V values were stable with a mean of 1.26 B 0.04 and exhibited no significant alteration from month to month. The serum albumin values were also in normal limits (3.93 B 0.36 g/dl) with no major change. The mean mid-month BUN level was 72.7 B 14.2 mg/dl and significantly higher than the mean BUN level obtained in the first (64.9 B 11.2 mg/dl, p! 0.001). A significant increase was also observed in mean serum K levels in the mid-month analysis compared with the values obtained in regular first- examinations (5.60 B 0.70 versus 5.05 B 0.91 meq/l, p! 0.001). The IWG values during the mid-month period were 1,766 B 672 g and they were significantly higher than the values observed in Discussion Compliance behavior is difficult to address in end-stage renal disease, however must be dealt with in planning care, particularly for long-term maintenance dialysis patients. Numerous studies have attempted to investigate factors associated with inadequate adherence and many cognitive and emotional variables, behavioral patterns, health beliefs and sociodemographic parameters were assigned as predictors of noncompliance [13]. However, cognitive and behavioral factors rather than demographic characteristics were found to be major determinants of compliance in most studies. Social support, personality variables, psychological distress, patient-staff relationships and even minor ly stresses were all previously demonstrated to alter the biochemical measures of compliance [4, 5, 9, 14]. As two recent studies put forward the close relationship between compliance and survival [2, 3], there is little doubt that the evaluation and control of confounding factors for compliance is essential for the proper management of HD treatment. Compliance in Hemodialysis Patients Blood Purif 1998;16:

4 BUN (mg/dl) K (meq/l) a First 100 a First Midmonth 4.6 Midmonth Fig. 1. BUN, serum K, serum PO 4 and IWG values obtained in the first s of a 6-month study period and mid-month values obtained in the second and fifth months. Values were expressed as mean B SD. a p! 0.001, b p! 0.05, c not significant (mid-month versus first ). IWG (g) 1,900 b 5.6 1, PO (mg/dl) 1, , , First c 1,400 First Midmonth 4.6 Midmonth In the present study, we observed a significant deviation in the compliance status of the study population as mid-month biochemical measures were concerned. We noticed a decrease in the compliance status of dietary adherence as mid-month BUN and K levels displayed higher predialysis levels. Even though the IWGs of our patients were not in extreme limits when compared with a large survey of US patients [3], the difference between mid-month and first- values (1,766 B 672 versus 1,608 B 609 g) is noticeable and implies a change in fluid and/or salt intake. The variations in MAP values were also in accordance with the difference observed in IWGs. The nonsignificant increase in predialysis serum PO 4 values might indicate that medication compliance was altered but not as much as dietary and fluid restriction parameters. The present findings with regard to the lack of significant relationships between altered compliance and sociodemographic variables are compatible with previous reports. However, it could not be possible to reach satisfactory relationships as we have evaluated a relatively small number of patients (54 patients) within a limited time period (6 months). The only significant relationship was between the age of the patients and the differences observed in predialysis serum PO 4 levels. This could be attributed to the occurrence of memory deficits in the elderly population. In a previous study, the compliance status of the elderly population was less impressive with regard to predialysis serum PO 4 levels compared to K values [15]. The main clinical relevance of the present study is the observation of alterations in the compliance status when biochemical indices are monitored in an unanticipated setting. This could be associated with the alterations in behavioral characteristics of the patient population. It was known that ritual versus reasoned compliance or passive versus active types of adherence to treatment regimen might affect compliance parameters. Ritual or passive compliance is a relatively inflexible 278 Blood Purif 1998;16: Arici/Altun/Usalan/Ulusoy/Erdem/ Yasavul/Turgan/Çaglar

5 behavior, in which the patient follows the prescribed regimen strictly without any modifications. However, reasoned or active compliance migh have some flexibility to accommodate the individual s day-to-day circumstances [16]. The predictors of such behaviors have not settled, but patients with the reasoned compliance behavior can learn to manipulate the system. In a 9-year study, O Brien observed a decrease in compliance of many individuals in a re-interview performed 3 years after the first interview. This finding was attributed to the decrease in ritual compliance and initiating a reasoned compliance; however, it might bring the danger of handling the system beyond the acceptable boundaries of active treatment compliance [16]. The unanticipated control of biochemical indices might uncover the deviation in behavioral patterns of compliance in HD patients. Patients might prepare themselves for the control periods and then alter their adherence characteristics. Some still manage their day-to-day requirements without jeopardizing fluid and electrolyte balance; however, some individuals expand the flexibility of reasoned compliance into a dangerous zone. Such in alteration could be associated with increased morbidity, even mortality like the behavior of skipping an HD session [3]. However, the probable deviation in the behavioral pattern of our study population should be assessed with the inclusion of emotional and cognitive attitudes of the patients and monitoring style of the hospital staff [17]. In summary, the majority of compliance data depends on monthly laboratory measures and the difference observed upon shift of test request timing was distinctive. This serves to indicate not only the importance of establishing more appropriate methodological instruments in studies of compliance, but also the probable effect of altered behavioral characteristics on compliance parameters. Insight into mechanisms and consequences of such differences might provide additional means for the actual assessment and managing problems of compliance in patients on chronic HD treatment. Acknowledgments We are grateful to nursing staff of the hemodialysis unit for cooperating in this study. We also appreciate volunteer participation of our patients. This work was presented, in part, at the XXXVth Congress of the European Renal Association European Dialysis and Transplant Association, Rimini, Italy, 6 9 June OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO References 1 Morduchowicz G, Sulkes J, Aizic S, Gabbay U, Winkler J, Boner G: Compliance in hemodialysis patients: A multivariate regression analysis. Nephron 1993;64: Kimmel PL, Peterson RA, Weihs KL, Simmens SJ, Alleyne S, Cruz I, Veis JH: Psychological factors, behavioral compliance and survival in urban hemodialysis patients. Kidney Int 1998;54: Leggat JE, Orzol SM, Hulbert-Shearon TE, Golber TA, Jones CA, Held PJ, Port FK: Noncompliance in hemodialysis: Predictors and survival analysis. Am J Kidney Dis 1998;32: Manley M, Sweeney J: Assessment of compliance in hemodialysis adaptation. J Psychosom Res 1986;30: Sensky T, Leger C, Gilmour S: Psychosocial and cognitive factors associated with adherence to dietary and fluid restriction regimens by people on chronic haemodialysis. Psychother Psychosom 1996;65: Ferraro KF, Dixon RD, Kinlaw BJR: Measuring compliance among in-center hemodialysis patients. Dial Transplant 1986;15: Compliance in Hemodialysis Patients Blood Purif 1998;16:

6 7 Simmens S, Kimmel PL, Kobrin S, Reiss D: Multidimensional assessment of compliance in two dialysis units. J Am Soc Nephrol 1991;2: Blackburn SL: Dietary compliance of chronic hemodialysis patients. J Am Diet Assoc 1977;70: Hitchcock PB, Brantley PJ, Jones GN, McKnight GT: Stress and social support as predictors of dietary compliance in hemodialysis patients. Behav Med 1992;18: Gardner MD, Henderson AR: Testrequest patterns for clinical chemistry in a British and Canadian Renal dialysis unit. Clin Chem 1983;29: Dillingham MA, Anderson RJ: Selected health care maintenance policies in chronic dialysis centers. Am J Kidney Dis 1985;6: Daugirdas JT: Second generation logarithmic estimates of single pool variable volume of Kt/V: An analysis of causes and an approach to evaluation. J Am Soc Nephrol 1993; 4: Hoover H: Compliance in hemodialysis patients: A review of the literature. J Am Diet Assoc 1989;89: Schneider MS, Friend R, Whitaker P, Wadhwa NK: Fluid noncompliance and symptomatology in endstage renal disease: Cognitive and emotional variables. Health Psychol 1991;10: McKevitt PM, Jones JF, Lane DA, Marion RR: The elderly on dialysis: Some considerations in compliance. Am J Kidney Dis 1990;16: O Brien ME: Compliance behavior and long-term maintenance dialysis. Am J Kidney Dis 1990;15: Christensen AJ, Moran PJ, Lawton WJ, Stallman D, Voigts AL: Monitoring attentional style and medical regimen adherence in hemodialysis patients. Health Psychol 1997;16: Blood Purif 1998;16: Arici/Altun/Usalan/Ulusoy/Erdem/ Yasavul/Turgan/Çaglar