Digital health interventions for cancer-related cognitive impairment in breast cancer patients: A scoping review

Review question

The specific research questions addressed in this review are: (1) What are the intervention strategies for CRCI in breast cancer patients, and what are their general characteristics? (2) What techniques, procedures, and content elements are used in DHIs? Which BCTs are incorporated? (3) What outcome indicators are used, and what is the effectiveness of these intervention strategies?

Eligibility criteria

The study utilized inclusion and exclusion criteria based on the Population, Intervention, Comparison, Outcomes, and Study Design (PICOS) framework. ³⁵ Inclusion criteria: (1) Population: Research focused on patients aged 18 or older diagnosed with breast cancer, who had received chemotherapy, radiation, hormone therapy, and/or surgery, and who were evaluated for chemotherapy-related cognitive impairments or shown signs of cognitive deterioration. (2) Intervention: DHIs designed to enhance cognitive impairments in breast cancer patients. This includes, but is not restricted to, cognitive training software, online psychoeducational courses, telemedicine consultations, mobile health applications, and similar resources. (3) Comparison: The control group may consist of standard treatments and care, or alternative non-DHIs such as classic psychoeducation or in-person cognitive training. (4) Outcome: Research must use at least one metric pertaining to overall cognitive functioning, specific cognitive domains (e.g. memory, attention, executive functioning, language ability), or objective neuropsychological evaluations, as primary or secondary outcome measures. (5) Study Design: The included study types comprise randomized controlled trials, experimental studies, feasibility studies, and mixed-method studies. Exclusion criteria: (1) Literature not accessible in full text; (2) Literature published multiple times; (3) Studies that offer merely a cursory overview of the intervention, precluding the identification and coding of behavior change techniques in later phases.

Data sources and search strategy

The system searched nine databases, including PubMed, CINAHL, Web of Science, ProQuest, Cochrane Library, Embase, PsycINFO, China National Knowledge Infrastructure, Wan fang Data. The search utilized a combination of subject phrases, keywords, and Boolean operators, together with citation analysis, undertaken from the library's inception until 9 February 2025. To augment the thoroughness of our research, gray literature was systematically searched via specialized databases and platforms. ProQuest, as an extensive database, was employed to obtain pertinent doctoral and master's theses. In a similar manner, Chinese doctorate and master's theses were retrieved from the China National Knowledge Infrastructure database, a principal repository for academic dissertations in China. The searches for gray literature utilized analogous keywords and Boolean operators as those applied to peer-reviewed journal articles, concentrating on terms associated with “Breast Neoplasm,” “Cognitive Dysfunctions,” “chemotherapy-related cognitive impairment,” and “digital health intervention” (as outlined in Table 1).

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Table 1.

Search strategies and search terms.

Key concepts	Search terms
Breast neoplasm	breast neoplasm OR breast neoplasms OR breast carcinoma OR breast carcinomas OR breast malignan* OR breast tumor OR breast tumors OR breast tumour OR breast tumours OR breast cancer OR breast cancers OR mammary cancer OR mammary cancers
Cognitive dysfunctions	Cognitive Dysfunctions OR Cognitive Disorder OR Cognitive Impairments OR Cognitive Decline
Chemotherapy-related cognitive impairment	CRCI OR Chemotherapy Related Cognitive Impairment OR Chemotherapy- Related Cognitive Impairments OR Chemotherapy-Induced Cognitive Dysfunction OR Chemotherapy Induced Cognitive Dysfunction OR Chemo-Fog OR Chemo Fog OR Chemotherapy-Induced Cognitive Impairments OR Chemotherapy Induced Cognitive Impairments OR Chemotherapy-Induced Cognitive Impairment OR Chemotherapy Induced Cognitive Impairment OR Chemotherapy-Related Cognitive Dysfunction OR Chemotherapy Related Cognitive Dysfunction OR chemotherapy related cognitive Dysfunction OR Chemo brain
Digital health intervention	Telemedicine OR mobile health OR ehealth OR mhealth OR telehealth OR internet OR online OR application OR App OR platform OR WeChat OR web OR digital virtual OR virtual reality OR cyber OR computer OR mobile OR smartphone OR phone OR Virtual Medicine

CRCI: cancer-related cognitive impairment.

Study selection

The acquired material was loaded into EndNote reference management software. Two researchers, both proficient in evidence-based nursing, independently evaluated the studies according to the established inclusion and exclusion criteria. This procedure entailed examining the titles and abstracts, thereafter acquiring and further evaluating the complete texts of pertinent papers. Disputes were settled through collaborative dialogue or adjudicated by an impartial third researcher.

The data extraction for the included studies was conducted independently by two researchers, with any differences addressed and resolved through the participation of a third researcher. A self-created form was utilized to gather general study information, encompassing: authors, country of origin, study design, sample size, components of the DHI (including techniques, procedures, and content elements), control group interventions, intervention duration, cognitive functioning assessment tools, and intervention outcomes. The cognitive function assessment tools are summarized in Table 2. A detailed description of the cognitive assessment tool is included as a separate comprehensive table in Supplementary File 1. The extracted data are summarized in Table 3.

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Table 2.

Tools for measuring cognitive function.

Category			Cognitive function assessment tools
1. Objective Cognitive Function Assessment Tools	1.1 Comprehensive Neuropsychological Assessment Scales	1.1.1. Integrated Neuropsychological Assessment Battery	Neuropsychological Assessment Battery (NAB) 36 NIH Toolbox Cognitive Battery (NIHTB-CB) 37 CNS Vital Signs® 38
		1.1.2 General Cognitive Screening Tools	Montreal Cognitive Assessment (MoCA)38–41
	1.2 Specific Cognitive Domain Assessment Tools	1.2.1 Memory Function	1.2.1.1 Verbal Learning and Memory	Hopkins Verbal Learning Test (HVLT) 36 Rey Auditory Verbal Learning Test (RAVLT) 42 California Verbal Learning Test (CVLT) 43 Selective Reminding Task (SRT)44,45Verbal Learning Memory Test (VLMT)36,46 Auditory Consonant Trigrams (ACT) Test 47
			1.2.1.2 Visuospatial Memory	Rey-Osterrieth Complex Figure (ROCF) 46 Corsi Block-Tapping Test (CBTT) 42 Brief Visuospatial Memory Test, Revised (BVMT-R) 43
		1.2.2 Attention and Working Memory	1.2.2.1 Attention Span and Sustained Attention	Digit Span Task42,44–46Paced Auditory Serial Addition Test (PASAT) 48 Brief Test of Attention (BTA)44,45
			1.2.2.2 Selective Attention and Inhibitory Control	Stroop Colour and Word Test (SCWT) 42
		1.2.3 Executive Function	Trail Making Test (TMT)42,45,47,49,50
		1.2.4 Processing Speed	Digit Symbol Substitution Test (DSST) 42 Symbol Digit Modalities Test (SDMT) 43
		1.2.5 Language Function	Verbal Fluency Test 42
		1.2.6 Visuospatial Function	Rey-Osterrieth Complex Figure (ROCF) 46
2. Subjective Cognitive Function Assessment Tools	2.1 Patient Self- Reported Tools	Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog)37,38,42–46,49–53Cognitive Failures Questionnaire (CFQ)24,48PROMIS Applied Cognition 51

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Table 3.

Overview of included studies.

No.	First Author Country Year	Study design	Sample size	Digital components of intervention			Comparison group	Duration	Tools for measuring Cognitive function	Effectiveness of intervention
				Technique	Procedure	Content element
1	Robert 43 American2016	RCT	47	Computer	Tandbergcentric (CBT)1700 MXP	Cognitive Behavioral	supportivetherapy	8 weeks	CVLT	1. Improvementsin cognitivefunction,anxiety, fatigueand quality oflife
						Therapy			FACT-Cog
						1. Education			SDMT
						2. Self-awareness training
						3. Stress management and
						self-regulation
						4. Cognitive compensation				2. High patientsatisfaction
						strategy training (memory,
						language skills, attention,
						executive ability)
2	Jamie 51	Feasibility	61	Computer	Tandbergcentric1700 MXP	Six sessions in total	—	6 weeks	FACT-Cog	Significantimprovementsin cognitivefunction,anxiety, fatigueand loneliness.
	American					Week 1: Program			PROMIS
	2020	Study				Introduction and Overview			Applied
						Week 2: Stress			Cognition
						Management and
						Relaxation Techniques
						Week 3: Emotion
						Management and
						Cognitive Strategies
						Week 4: Attention
						Training
						Week 5: Memory
						Enhancement Strategies
						Week 6: Problem Solving
						and Social Support
						Interventions cover
						attention, memory, and executive training
3	Ángela 49 Spanish2022	RCT	98	Computer	NeuroNation©	1. Cognitive training	routine care	12 weeks	TMT	Improvement incognitivefunctioning
						(attention, memory, daily			FACT-Cog
						living skills training)
						2. Adaptive training:
						including stress
						management, relaxation
						techniques, problem
						solving training, energy
						conservation and time
						Management3. Homework
4	Alyssa 37 Canada2023	Mixedresearch	18	Computer	Zoom	1. Yoga program includes	routine care	8 weeks	NIHTB-CB	Improvement incognitivefunctioning
					NeuroNati	breathing exercises,			FACT-Cog
					on©	meditation, asana practice
						and relaxation techniques
						2. Interventions cover
						attention, memory,
						language, executive
5	Jamie 50 American2022	FeasibilityStudy	30	Computer	—	Functioning trainingCombining motor and	wait - list	4 weeks	TMT	Improvement incognitivefunctioning
						game-based cognitive	control		FACT-Cog
						training:
						1. Exercise
						2. Cognitive games
						including short-term
						memory and simple
						arithmetic
						Interventions cover:
						processing speed,
						executive functioning,
						short-term memory
6	Diane 44 American2023	RCT	35	Computer	BrainHQ	1. Computerized cognitive	1. Global	10 weeks	TMT	Improvement incognitivefunctioning
						training: including	Cognitive		SRT
						chronological order	Stimulating		Digit Span Task
						judgment, discrimination,	based		BTA
						spatial matching,	Games:		FACT-Cog
						command following, and	including
						narrative memory tasks.	crossword
						2. Interventions covered:	puzzles,
						memory, executive	Sudoku
						functioning, attention	2. Interventio
							ns cover:
							attention,
							memory,
							executive
							functioning,
							speed of
							information processing
7	Anne 24 Belgium2020	RCT	46	Computer	Aquasnap	Video Game Cognitive	routine care	6 months	CFQ	Positive effects
					（MyCQ	Training				on cognitive
					™）	Targets five cognitive				functioning,
						domains:				especially
						Attention, Working				improvements
						Memory, SituationalMemory, ExecutiveFunctioning				in subjective cognitive functioning
8	Jennifer 45 American2023	FeasibilityStudy	21	Computer	—	1. Cognitive games include	routine care	6 weeks	TMT	Improvement inboth cognitivefunctioning andemotional state
						Short Term Memory and			SRT
						Simple Arithmetic.			Digit Span Task
						2. Training tasks: including			BTA
						Memory Ball Recall,			FACT-Cog
						Ultimate Word Master
						(UWM), and Neurogrow.
						involves training in
						attention, working
						memory, situational
						memory, executive functioning, and more!
9	Damholdt 48 Denmark2016	RCT	157	Computer	Happy	Web-based cognitive	wait - list	6 weeks	PASAT	Training had apositive effecton memory andconcentration,but nosignificantsubjectivecognitivefunctionimprovements were found.
					neuron	training + telephone	control		CFQ
					Pro©	support
						1. The cognitive training
						program covers six
						cognitive domains:
						Attention, Memory,
						Working Memory
						2. Each task is designed as
						a computer game
10	Karl 46 Germany2024	RCT	40	Computer	NeuroNati	Network cognitive	—	14 weeks	ROCF	1. significantimprovement inoverallcognitive andexecutivefunctioning
					on	training:			Digit Span Task
						1. Training tasks are			VLMT
						designed in the form of			FACT-Cog
						games
						2. The training consists of
						16 tasks, covering working				2. no significantimprovementwas seen inquality of life,depression and fatigue.
						memory
11	Giulia 38 France2021	FeasibilityStudy	20	Computer	HappyNeu	1. Cyber-adaptive physical	—	12 weeks	MoCA	—
					ron ®	activity (warm-up, muscle			CNS Vital
					Mooven®	strengthening activities,			Signs®
						stretching)			FACT-Cog
						2. Cyber Cognitive
						Stimulation (training
						attention, memory,
						executive function,
						language, visuospatial skills)
12	Giulia 52 France2024	Feasibility	55	Computer	HappyNeu	Digital Cognitive	—	60	FACT-Cog	1. Software hasusability
					ron	Stimulation Training		minutes
		Study			PRESCO	training covers Attention,				2. Patientcompliance ishigh
						memory, executive
						function, language, logic, visuospatial ability, etc.
13	Yang 39 China2023	RCT	104	VR	Homebrewprogram	Cognitive rehabilitation	routine care	8 weeks	MoCA	1. Cognitivefunctionimprovement
						training includes:
						1. Executive training: tasks
						such as rowing a boat,				2. Improvementof daily livingskills
						playing ping-pong, cutting
						a cake, etc. with an avatar
						2. Attention training: tasks				3. Improved self-managementefficacy
						such as virtual mazes,
						vehicle lane changing,
						crossroads, etc.				4. Highercompliance
						3. Memory training:
						through auditory, visual,
						logical, numerical, motor
						and associative memory training.
14	Chen 40 China2019	RCT	80	VR	Homebrewprogram	Virtual Cognitive	routine care	8 weeks	MoCA	1. Cognitivefunctionimprovement
						Rehabilitation Training
						System
						1. The training program				2. Improvementof daily livingskills
						includes memory training,
						motor memory, auditory
						memory, logical memory,				3. Improved self-managementefficacy
						visual memory, digital
						memory and associative
						memory.				4. Highercompliance
						2. Each module enhances
						the patient's cognitive
						function through virtual
						scenes and game tasks.
						3. Training difficulty
						ranges from simple to difficult
15	Yang 41 China2021	RCT	96	VR	Homebrewprogram	Virtual Cognitive	Routine	8 weeks	MoCA	1. Cognitivefunctionimprovement
						Rehabilitation Training	cognitive
						1. Training content:	interventions
						including memory				2. Improvementof daily livingskills
						training, motor memory,
						logical memory, auditory
						memory, visual memory,				3. Improved self-managementefficacy
						numerical memory and
						associative memory.
						2. The training is				4. Highercompliance
						conducted through virtual
						scenes and virtual objects,
						using somatosensory
						interactive equipment.
						3. Training difficulty
						ranges from simple to difficult
16	Noelia 47 Spanish2017	RCT	81	Computer	e-CUIDATE	Internet customized	routine care	8 weeks	TMT	Improvement incognitivefunctioning
						exercise program:			ACT
						including warm-up,
						aerobic and resistance exercise, relaxation
17	Lyn 53 American2015	RCT	118	Computer	Zoom	1. Live Delivery	routine care	5 weeks	FACT-Cog	Significantimprovementsin health-relatedquality of life,fatiguecognitivefunctioning,mental health,psychologicaldistress andsleep quality were observed.
						Telemedicine Delivery
						2. All content includes:
						educational component,
						interactive component,
						home exercises
						3. Training of attention,
						memory, executive
						function
18	Maria 42 Spanish2024	RCT	176	Computer	ICOnnecta’t	ICOnnecta't Platform +	ICOnnecta't	12	RAVLT	1. Improvedcognitivefunctioning
						Cognition Module	program,	months	TMT
						(ICOgnition) includes the	including		Digit Span Task
						following components:	psychosocial		CBTT	2. Reducedemotionaldistress
						Cognitive Screening,	screening,		Verbal Fluency
						Cognitive	psychoeduca		Test
						Psychoeducation, Online	tion,		SCWT	3. Improvedquality of life
						Cognitive Training:	community		DSST
						Including Memory,	support and		FACT-Cog	4. Higheradherence
						Attention, and	online group
						Visuospatial Orientation Skills Training	psychotherapy
19	Gregory 36 American2016	FeasibilityStudy	6	Robotics	BrightArm	1. Virtual rehabilitation	—	8 weeks	HVLT	1. Improved cognitive Function
				VR	Duo	games include: motor			NAB
						training, Emotional and			BVMT-R	2. Pain reduction
						cognitive training				3. Mood Improvement
						2. Training executive				4. Improvement in daily living skills
						function, attention, short-term and delayed memory, working memory				5. High technology acceptance

VR: virtual reality; RCT: randomized controlled trial.

BCTs were classified utilizing the approach established by Michie et al. (version 1), which organizes 93 unique BCTs into 16 categories, so offering a consistent framework for the identification of BCTs in behavior change interventions. The coding was conducted independently by two reviewers (YXC and YZ), with any discrepancies addressed through deliberation with a third reviewer (WYH) until a consensus was achieved. Table 4 delineates the specific BCTs incorporated in the DHI techniques.

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Table 4.

BCTs involved in intervention strategies.

Inclusion of literature	Goals and planning	Feedback and monitoring	Social suppo rt	Shaping knowled ge	Natural consequences	Comparison of behavior	Association s	Repetition and substitution	Reward and threat	Regulation	Antecedents
1. Robert 43	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes	No	Yes	Yes
2. Jamie 51	Yes	No	Yes	Yes	No	No	No	Yes	No	No	No
3. Ángela 49	Yes	Yes	Yes	Yes	No	No	No	Yes	No	No	No
4. Alyssa 37	Yes	No	Yes	Yes	No	Yes	Yes	Yes	Yes	No	Yes
5. Jamie 50	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes	No	No	No
6. Diane 44	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes	No	No	No
7. Anne 24	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes	No	No	No
8. Jennifer 45	Yes	Yes	Yes	Yes	No	No	No	Yes	Yes	No	No
9. Damholdt 48	Yes	Yes	Yes	No	No	No	No	Yes	No	No	No
10. Karl 46	Yes	Yes	Yes	No	No	Yes	Yes	Yes	Yes	No	Yes
11. Giulia 38	Yes	Yes	Yes	No	Yes	No	Yes	Yes	Yes	No	No
12. Giulia 52	Yes	Yes	Yes	No	Yes	No	No	No	Yes	No	No
13. Yang 39	Yes	Yes	Yes	No	Yes	No	Yes	No	Yes	No	No
14. Chen 40	Yes	Yes	Yes	No	No	No	Yes	Yes	No	No	No
15. Yang 41	Yes	Yes	Yes	No	No	No	Yes	Yes	No	No	No
16. Noelia 47	Yes	Yes	Yes	No	Yes	Yes	No	Yes	No	No	No
17. Lyn 53	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	No	No	Yes
18. Maria 42	Yes	Yes	Yes	Yes	No	No	No	Yes	Yes	No	No
19. Gregory 36	Yes	Yes	Yes	No	No	No	No	No	No	No	No

BCT: behavioral change technique.

Selection of sources of evidence

A total of 636 articles were obtained during the initial screening, 21 articles were incorporated from retrospective references, and 545 articles persisted following the removal of duplicates. Following the review of titles and abstracts, 278 articles were excluded; an additional 13 articles were dismissed; 254 articles were eliminated upon full-text evaluation (comprising 51 articles that did not align with the study population, 149 articles lacking cognitive function assessment in the outcome measures, and 35 articles that did not incorporate BCTs in the intervention descriptions); ultimately, 19 articles were selected for inclusion in the final literature review. The process of study selection is illustrated in Figure 1, the study selection diagram.

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Figure 1.

Study selection diagram.

Characteristics and results of sources of evidence

A total of 19 papers were included in this study, published between 2015 and 2024. The geographic distribution of the included literature was broad, with seven from the United States,^{36,43–45,50,51,53} three from China,^39–41 three from Spain,^42,47,49 two from France,^38,52 one from Germany, ⁴⁶ one from Denmark, ⁴⁸ one from Belgium, ²⁴ and one from Canada. ³⁷ Study types included randomized controlled studies (n = 12),^{24,39–44,46–49,53} feasibility studies (n = 6)^{36,38,45,50–52} and mixed studies (n = 1). ³⁷ Study sample sizes ranged from 6 to 176. The study subjects were all breast cancer patients with an age range of 18 years and above.

Types of technologies, applications for digital health interventions

In this study, there were various types of DHI technologies, mainly including computer technology, virtual reality (VR) technology, and robotics, with computer technology being the most common. The length of the intervention ranged from 60 min to 12 months, with most studies ranging from 8 weeks to 12 weeks. ① Fifteen studies^{24,37,38,42–53} (78.94%) used computerized technology for cognitive interventions, with commonly used tools including the Tandberg centric 1700 MXP (2),^43,51 NeuroNation^© (3),^37,46,49 HappyNeuron series (3 items),^38,48,52 Zoom (2 items),^37,53 BrainHQ program (1 item), ⁴⁴ Aquasnap (MyCQ™) (1 item), ²⁴ e-CUIDATE system (1 item), ⁴⁷ and ICOnnecta't program (1 item). ⁴² Computerized cognitive training uses computer programs and software to enhance cognitive functioning and usually involves a series of organized, interactive computer tasks designed to improve cognitive domains such as attention, memory, and executive functioning. ⁵⁴ The computer technology interventions in this study covered cognitive behavioral therapy, cognitive training, adaptive training, and homework. ② Three studies^39–41 (15.78%) used VR technology for cognitive interventions, and all of them used homemade VR game programs combined with virtual scenarios and somatosensory interactive devices to implement cognitive rehabilitation training. VR technology is a technology that generates a three-dimensional virtual environment that can be interacted with through computer simulation, allowing users to feel like they are in the realm of the real world, ⁵⁵ The application of VR in cognitive rehabilitation is to improve and rehabilitate cognitive functions by creating immersive virtual environments that allow users to perform various cognitive training tasks in a virtual scene. The VR technology interventions in this study included a virtual cognitive rehabilitation training system, virtual scenes, and game tasks. ③ One study ³⁶ (5.26%) conducted an innovative attempt to combine robotics and VR, using the BrightArm Duo rehabilitation system, which integrates robotic assistance with virtual rehabilitation games for motor and cognitive training. The robot improves user engagement and cognitive recovery through personalized training programs, real-time feedback, and gamified design.

Content elements of digital health interventions

The content elements of the DHI focused on six cognitive training domains, as follows: ① 15 studies^{24,37–41,43–45,48,49,51–53} involved attention training: using self-directed training, ⁴³ positive thinking meditation,^37,51 task-switching, ³⁷ spatial matching, ⁴⁴ and temporal order judgment. ⁴⁴ This was done in a variety of ways. Common tasks include “concentration” exercises,^49,51 breath control exercises, ³⁷ distraction tasks such as “Pay Attention!”,^38,52 “Private Eye!”,^38,52 virtual mazes,^39–41 vehicle lane changing, ³⁹ and complex puzzles. ⁴² ② Seventeen studies^{24,36–46,48–52} involved memory training, covering short-term memory, long-term memory, and different types of memory tasks, such as verbal repetition, ⁴³ visualization strategies, ⁴³ mnemonics, ⁵¹ imagery, ⁵¹ memorization of words, numbers, or images,^36,42,49 and memorization of repetitions of specific yoga poses and sequences. ³⁷ ③ Three studies^37,38,52 dealt with language skills training: understanding and following instructions, ³⁷ vocabulary tests, vocabulary and language comprehension tasks such as “Split words,”^38,52 “Embroidery,”^38,52 and other communication tasks. ④ Eleven studies^{24,36,38,39,43–45,50–53} dealt with executive skills training: making an organized schedule, ⁴³ simple arithmetic, ⁵⁰ time-limited crossword puzzles, ⁴⁴ and problem-solving and decision-making tasks such as “Towers of Hanoi,”^38,52 “Basketball in New-York,”^38,52 tasks such as rowing a boat, playing ping-pong, and cutting a cake with an avatar, ³⁹ interactive exercises, ⁵³ and task training such as Breakout 3D ³⁶ : training executive functions by bouncing a virtual ball. ⑤ Three studies^38,42,52 involved training in visuospatial orientation skills: including training in spatial perception and visual processing tasks such as maze games, ⁴² 3D object rotation and puzzle games. ⁴² ⑥ One study ⁵² involved logic and numeracy training: it included logical reasoning tasks, such as “The Right Count” training task. ⑦ One study ⁴⁹ involved daily living skills training: helping patients to manage daily activities more effectively through energy management and time management skills.

Behavioral change techniques used in intervention strategies

The 19 studies included in this scoping review addressed a total of 11 categories of BCTs, as detailed in Table 3. All 19 studies used at least one category of behavior change technique. Seventeen studies^{24,36–50,52,53} used greater than five categories of BCTs. Intervention components used in intervention strategies included goals and plans^24,36–53 (setting specific cognitive training goals) (n = 19), feedback and monitoring^{24,38–41,43–50,52,55} (workbooks, telephone assessments, logs, online platforms to record) (n = 17), social support^24,36–53 (emotional support, informational support) (n = 19), Knowledge Shaping^{24,37,42–45,49–51,53} (instruction on how to conduct cognitive training, problem-solving training) (n = 10), Natural Consequences^{24,39,43,44,47,50,53} (Participants were able to directly perceive an improvement in cognitive functioning through self-reported assessments of cognitive functioning) (n = 9), Behavioral Comparison^{24,37,43,44,46,47,50,53} (role modeling by others) (n = 8), Connection^{37–41,46,53} (linking healthy behaviors to positive emotions and outcomes) (n = 7), Repetition and Substitution^{24,37,38,40,41,43–51,53,55} (diversified activities such as cognitive stimulation combined with physical activity to replace a single activities) (n = 16), Reward^{37–42,45,46,52} (social or material rewards for completing cognitive training tasks) (n = 7), Conditioning ⁴³ (relaxation training, stress management, emotion regulation) (n = 1), and Antecedents^37,43,46,53 (environmental changes e.g. community-centered group activities, videoconference interactions) (n = 4).

Measurement tools for cognitive functioning

This scoping review categorizes techniques for assessing cognitive function into two primary groups: objective assessments (neuropsychological tests) and subjective assessments (patient-reported outcomes (PROs)).

Neuropsychological examinations offer standardized and quantitative evaluations of cognitive functioning. These instruments are employed to assess general cognitive functioning and particular cognitive domains. A variety of neuropsychological assessments have been employed to evaluate overall cognitive functioning. The Montreal Cognitive Assessment was employed in four research.^38–41 Other tools for assessing overall cognitive function include the NIH Toolbox Cognitive Battery (n = 1), ³⁷ CNS Vital Signs^® (n = 1), ³⁸ and Neuropsychological Assessment Battery ³⁶ (n = 1).

In addition to the overall assessment, studies have targeted specific cognitive domains. In the area of memory functioning, assessment tools for verbal learning and memory include the Hopkins Verbal Learning Test, ³⁶ Rey Auditory Verbal Learning Test, ⁴² California Verbal Learning Test ⁴³ (each in one study), Selective Reminding Task,^44,45 and Verbal Learning Memory Test^36,46 (both in two studies). The Auditory Consonant Trigrams Test ⁴⁷ (n = 1) was also used in this domain. For the assessment of visuospatial memory, Rey-Osterrieth Complex Figure, ⁴⁶ the Corsi Block-Tapping Test, ⁴² and the Brief Visuospatial Memory Test, Revised ⁴³ (each in one study) were used. Executive power was assessed by the Trail Making Test^{42,45,47,49,50} (n = 5), and attention instruments included the Digit Span Task,^42,44–46 the Paced Auditory Serial Addition Test ⁴⁸ (n = 1), the Brief Test of Attention^44,45 (n = 2), and the Stroop Colour Word Test ⁴² (n = 1). Processing speed was assessed with instruments such as the Digit Symbol Substitution Test ⁴² (n = 1) and the Symbol Digit Modalities Test ⁴³ (n = 1). In addition, Verbal Fluency Test ⁴² (n = 1) and Rey-Osterrieth Complex Figure ⁴⁶ (n = 1) were used to assess verbal function and visuospatial function.

Subjective assessments, known as PROs, assess patients’ self- perceived cognitive changes and complaints. In terms of overall cognitive functioning, the most frequently used PRO is the Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog),^{37,38,42–46,49–53} which was used in 12 studies. Other PROs include the PROMIS Applied Cognition ⁵¹ (n = 1) and the Cognitive Failures Questionnaire^24,48 (n = 2).

Effectiveness of digital health interventions

In 18 studies,^{24,37,39–42,44–47,49–52,55} the results showed that DHIs had a significant improvement in the cognitive functioning of breast cancer patients. Among them, six studies^{36,37,42,43,51,53} also found that DHIs were effective in improving patients’ mood states, and the improvement in mood in turn facilitated the recovery of cognitive functioning, creating a virtuous cycle. In addition, two studies^42,53 showed that breast cancer patients’ quality of life was significantly improved after receiving DHIs. Meanwhile, five studies^39–42,52 found that patients’ satisfaction and compliance with DHIs were high, further demonstrating the feasibility and effectiveness of this intervention program.

Virtual reality and robotics in cognitive rehabilitation

VR provides an immersive training environment that markedly enhances cognitive function and daily life skills in breast cancer patients. Research indicates that VR therapies significantly enhance visuospatial abilities, attention, and memory, hence increasing cognitive functions and self-management skills.^39,40 Additionally, the use of robotics, such as the BrightArm Duo system, has expanded intervention dimensions by incorporating real-time feedback and personalized training. ³⁶ The BrightArm Duo system aims to rehabilitate upper limb motor function while concurrently providing cognitive training and emotional support via gamified tasks and VR environments. ⁵⁶ Future research should investigate the amalgamation of cognitive and affective therapies in rehabilitation to improve patient experiences and outcomes.

Content elements of digital health interventions

DHIs focus on six essential cognitive domains: attention, memory, executive functions, language, logic and numeracy, and visuospatial orientation. These domains are trained in a variety of ways, such as attention training through visual tracking tasks to improve concentration, ⁴⁹ and memory training through memory games and repetitive exercises to enhance memory capacity and efficiency.^24,48 In executive training, the combination of gamified design (e.g. “Towers of Hanoi”) and social interaction (Zoom group tasks)^38,52 significantly improves long-term adherence and treatment outcomes. This design methodology not only augmented the enjoyment of the tasks but also elevated the patients’ sense of belonging and participation through social interactions, so enhancing the overall therapy experience. The DHI significantly enhanced attention, memory, and executive function, offering patients an effective and sustainable treatment plan via Internet-based cognitive behavioral therapy, gamified design, and real-time feedback mechanisms. Future study should investigate the customization of personalized DHIs to align with the distinct needs and contexts of patients. For instance, creating more specialized training modules and task designs for patients of varying age demographics or disease classifications.

Behavior change techniques in digital health interventions

This analysis thoroughly analyzed the BCTs employed in DHIs for cognitive rehabilitation in breast cancer patients. The findings suggest that intervention strategies employ a diverse array of multidimensional methodologies to enhance cognitive function. “Goal setting and planning” evolved as a fundamental method, assisting patients in elucidating intervention aims and augmenting adherence through the establishment of specific cognitive goals (e.g. enhancing attention or memory). This corresponds with prior research indicating that goal-oriented interventions can significantly enhance self-efficacy. ⁴² Furthermore, “feedback and monitoring” facilitates real-time data tracking via workbooks and online platform records, enabling patients to dynamically modify training intensity. Research has also demonstrated that these strategies can improve behavioral maintenance through instant feedback.^38,52 Social support, as a prevalent method, alleviates patients’ psychological stress via emotional and informational assistance (e.g. group interactions, therapist guidance), potentially enhancing cognitive symptoms and underscoring the significance of psychosocial factors in CRCI interventions. ⁴² Significantly, procedures like “knowledge shaping” (n = 10) and “behavioral comparison” (n = 8) may assist patients in developing adaptive strategies through cognitive training instruction and role modeling. ⁵⁷ Conversely, “Repetition and Substitution” amalgamates many therapies, including cognitive stimulation and physical activity, or amplifies the efficacy of interventions via neuroplasticity mechanisms.^58,59 In contrast, the low utilization of “conditioning” and “antecedent” techniques suggests the need to further explore the mechanisms and scenarios of relaxation training and environmental adjustment in CRCI. ⁶⁰ Despite the fact that most of the existing studies used comprehensive BCTs, extrinsic motivators such as “rewards” (n = 7) were less frequently used, which may limit long-term behavioral maintenance.^21,61 Future research should investigate methods to enhance long-term patient engagement and adherence via extrinsic motivators (e.g. incentives), while employing digital platforms to deliver real-time feedback and facilitate dynamic adjustments in training intensity may significantly improve intervention efficacy. Augmented emotional and informational support (e.g. group engagement, therapist advice) can mitigate patients’ psychological stress and indirectly enhance cognitive symptoms.

Challenges and future directions

While current research has shown the substantial impact of DHIs on enhancing cognitive impairment in breast cancer patients, numerous problems and limits persist. Cognitive functioning is frequently neglected, mostly due to the absence of defined protocols, inadequate awareness of cognitive effects among healthcare providers, limitations in resources and time, and the unavailability of suitable assessment instruments. ⁴² Secondly, while research indicates that older breast cancer patients exhibit greater acceptance and compliance with digital cognitive stimuli, variations among distinct patient demographics may influence the acceptance rate. ⁵² In the future, it is essential to create more intuitive interfaces (e.g. streamlined operating procedures) and assess the efficacy of long-term incentives. Simultaneously, technical obstacles (e.g. device compatibility, financial constraints) must be resolved to mitigate the digital divide. ⁶² Moreover, despite the convenience and cost-effectiveness of DHIs, patients may encounter issues with device and network access or a lack of familiarity with digital tools, thereby constraining the generalizability of the intervention. The constraints of assessment instruments and the intricate influence of several factors (e.g. chemotherapy, endocrine therapy, psychological condition, etc.) on cognitive performance pose problems for intervention development.^63–65 While short-term impacts have been evidenced, long-term effects require further validation, and the majority of existing studies have concentrated on short-term observations, missing longitudinal research extending five years or beyond. Moreover, extensive investigations of DHIs remain constrained by resources and financing, thus restricting the scope and depth of the studies, thereby impacting the comprehensiveness and trustworthiness of the findings. Future research must address these challenges by enhancing intervention programs, increasing sample numbers, and investigating long-term impacts to improve the efficacy and generalizability of therapies.

In contemplating the future advancement of DHIs for breast cancer patients, several critical directions warrant attention. Initially, the design of tailored interventions is crucial for enhancing outcomes. Patients with breast cancer exhibit varying forms of cognitive impairment, making it essential to tailor interventions according to their cognitive function and specific requirements. Employing artificial intelligence and big data analytics to monitor patients’ cognitive alterations in real time and adapt intervention tactics accordingly can enhance the precision and efficacy of therapies. The creation and execution of DHIs necessitate interdisciplinary cooperation. Interdisciplinary collaboration among medicine, nursing, psychology, and computer science, particularly in data collecting, analysis, and privacy protection, will establish a more robust foundation for future interventions. Consequently, interdisciplinary collaboration will be essential for the effective implementation of DHIs. Third, while current research has offered initial indications that DHIs can enhance cognitive function, the precise pathways are not fully elucidated. Future research should concentrate on boosting cognitive ability through the stimulation of neuroplasticity and the optimization of brain network coordination, thereby elucidating its biological foundations and offering theoretical support for intervention strategies. The long-term consequences of DHIs and patient satisfaction are critical factors that must not be overlooked. Notwithstanding the substantial immediate results of the intervention, the patients’ acceptance and happiness, along with the sustainability of the long-term impacts, remain critical inquiries that require urgent exploration in forthcoming investigations. Consequently, longitudinal follow-up studies and patient feedback will be essential to refine the intervention program and augment its practical applicability.

Strengths and limitations

This study, unlike other systematic studies, further demonstrates the capacity of DHIs to include various BCTs. Conventional non-pharmacological interventions (e.g. psychoeducation, fitness programs), while demonstrated to be successful, do not possess the personalized and data-informed attributes of DHIs. This paper is the inaugural systematic summary of the application model of BCTs, addressing the research gap in CRCI management. The review indicated that DHIs markedly enhanced cognitive functioning, especially in the areas of attention, memory, and executive functioning. Moreover, research has highlighted the beneficial effects of DHIs on emotional well-being and overall quality of life, with numerous studies indicating elevated patient satisfaction and adherence to DHIs. Nonetheless, limits in research persist. The significant heterogeneity among the included studies, characterized by substantial variations in sample size and intervention duration, may compromise the generalizability of the findings. Additionally, the absence of long-term follow-up data, particularly regarding the validation of effects beyond 1 year, constrains the evaluation of the enduring impacts of DHIs. Moreover, technological obstacles (e.g. device compatibility, financial constraints) and variations among patient demographics (e.g. age, digital literacy) may have resulted in disparate rates of intervention adoption, while insufficient descriptions of BCTs in certain trials exacerbated the challenges of coding and analysis. The variety of cognitive function testing techniques and the intricate influence of confounding variables (e.g. chemotherapy, psychological condition) may undermine the trustworthiness of the results.