Page 137 - Exploring the Potential of Self-Monitoring Kidney Function After Transplantation - Céline van Lint

Self-monitoring: the reliability of patient-reported data 135
Adherence to requested measurement frequency
Adherence to requested measurement frequency according to device logged data (did patients perform the requested number of measurements?) and adherence to SMSS logged data (if patients performed a measured, did they register the requested number of measurements?) is shown in figure 3. During phase 1 (daily measurements) adherence to the requested number of creatinine measurements was lowest with 79%. Subsequently, adherence rose to over 90% during phase 2 (measuring every other day) and 3 (measuring twice a week) and then decreased to 85% during phase 4 (measuring weekly). Four patients performed less than 75% of the requested measurements throughout two or more phases. For registration of the requested number of creatinine measurements this same pattern is shown, although the percentage of non-adherent patients is higher during all phases. Eight patients were non-adherent during two or more phases regarding registration of the requested number of measurements.
To control for the potential influence of hospitalization on level of adherence to measurement and registration protocol, we repeated our analysis with all hospitalized patients excluded. Total number of hospitalized patients was 11 during phase 1, three during phase 2, seven during phase 3 and nine during phase 4. Excluding these patients did not change our initial findings.
Moment of registration
When looking at date of measurement versus date of registration of measurements, a mean delay of 4 days (SD 10) was found. The level of delay varied from 1 to 81 days. Seven patients (15%) always registered their test results on the day of measurement and 15 patients (31%) had an overall mean delay of less than one day between measurement and registration. Twenty-two patients (46%) had an overall mean delay of more than three days, ranging up to a mean difference of 29 days between date of measurement and date of registration. One could hypothesize that patients do not feel the need to register their measurement online if their level of creatinine is stable. However, the feedback that was generated by the SMSS for measurements registered on the day of measurement versus measurements that were registered with delay did not differ: in both situations, patients were requested to repeat the measurement in about 7% of all registrations.
Reliability of registered data
Of the 43 patients included in the reliability analysis, the total number of values stored in the creatinine devices was 5779 and the total number of values registered in the SMSS was 4606. To investigate correspondence between measurement and registration, only days with an equal number of
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