Participants in the experimental group were oncology nurses employed at Hacettepe University Oncology Hospital who were provided access to CHEMONURS, a mobile chemotherapy drug guide application developed to support clinical decision-making and professional development. After completing a demographic form and baseline assessments using the Chemotherapy Practice Knowledge Scale and the Attitude Scale for Chemotherapy Practices, participants received a demo version of the app via a WhatsApp link. They were instructed to download the application onto their personal smartphones and use it freely over a six-month period during their routine clinical practice. No restrictions were placed on usage frequency to reflect real-world applicability; usage was monitored through embedded app analytics and nurse feedback. Daily reminders and follow-up communications were used to encourage continued engagement. Follow-up assessments of knowledge and attitudes were conducted at the 3rd and 6th months.

Participants in the control group were oncology nurses working at Hacettepe University Oncology Hospital who continued with their routine clinical duties without access to the CHEMONURS mobile application or any additional educational intervention. After completing the baseline assessment using the Chemotherapy Practice Knowledge Scale and the Attitude Scale for Chemotherapy Practices, no further intervention was provided. Follow-up assessments of knowledge and attitudes were conducted at the 3rd and 6th months, in parallel with the experimental group, to evaluate changes over time in the absence of the mobile application.

Participants in the mobile app group were oncology nurses employed at Hacettepe University Oncology Hospital who were provided access to CHEMONURS, a mobile chemotherapy drug guide application developed to support clinical decision-making and professional development. After completing a demographic form and baseline assessments using the Chemotherapy Practice Knowledge Scale and the Attitude Scale for Chemotherapy Practices, participants received a demo version of the app via a WhatsApp link. They were instructed to download the application onto their personal smartphones and use it freely over a six-month period during their routine clinical practice. No restrictions were placed on usage frequency to reflect real-world applicability; usage was monitored through embedded app analytics and nurse feedback. Daily reminders and follow-up communications were used to encourage continued engagement. Follow-up assessments of knowledge and attitudes were conducted at the 3rd and 6th months. U

This outcome evaluates the improvement in oncology nurses' knowledge of chemotherapy administration, assessed through the Chemotherapy Practice Knowledge Scale for Oncology Nurses. The items are scored to assess nurses' knowledge related to chemotherapy practices using a 3-point Likert scale: "I have knowledge = 3," "I am unsure = 2," and "I have no knowledge = 1." The scale consists of 44 items and four subdimensions. The total score ranges from a minimum of 44 to a maximum of 132, with higher scores indicating greater knowledge regarding chemotherapy administration.

This outcome measures changes in the attitudes of oncology nurses toward chemotherapy practices, using the Attitude Scale for Oncology Nurses Regarding Chemotherapy Practices. This scale was developed by Khan et al. (2012) to evaluate the attitudes of cancer nurses toward chemotherapy practices. It is a 4-point Likert-type scale with the following response options: 4 = Strongly Agree, 3 = Agree, 2 = Disagree, 1 = Strongly Disagree. The scale consists of two subdimensions: negative attitude (6 items) and positive attitude (4 items). The items under the negative attitude subdimension are reverse-scored when calculating the total score. The overall score ranges from a minimum of 10 to a maximum of 40, with higher scores indicating more positive attitudes toward chemotherapy practices.

Evaluation of the usability of the CHEMONURS mobile application as assessed by the Mobile Application Usability Scale at Month 3 and Month 6. The scale was created by Hoehle et al. (2016), and its Turkish adaptation was made by Güler in 2019. This tool provides information about the colors, text styles, font sizes, transitivity, application management, etc., used in the mobile application. The scale is a 7-point Likert-type measurement tool and consists of a total of 40 questions. The minimum score is 40, and the maximum score is 280, with higher scores indicating better usability.