Old age or cognitive decline? Examining the usability of a mobile health app for older Australians

Figures & data

Table 1. Profile of sample (n = 28).

Characteristics	Number, %
Gender
Male	11 (39%)
Female	17 (61%)
Education
Secondary	7 (25%)
Bachelor’s degree, diploma, advanced diploma	17 (61%)
Post-graduate degree (Masters, Phd)	4 (14%)
Age range
55 to 60	2 (7%)
61 to 70	7 (25%)
71 to 80	16 (57%)
81 to 85	3 (11%)
Occupation (prior to retirement)
Health sector (nursing, dentist, doctor, aged care)	5
Not stated	3
Engineering (software, civil) and geology	3
Management, clerical and administration (consultant, librarian, payroll, book-keeper, telephonist)_	10
Education (teacher, lecturer, childcare)	4
Science (botanist, marine scientist)	2
Personal services (massage therapist)	1

Table 2. Mean, median and standard deviations: scores for cognitive tests and usability.

	Cognitive tests			Task-based usability tests			Usability scores
Variables	Mini-Cog	TMT-A	TMT-B	TTT1	TTT2	TTT3	SUS	NPS
Mean	4.71	37.36	85.71	94.32	82.46	51.82	76.339	7.32
Median	5.00	37.00	73.50	78.50	73.00	43.50	77.50	8.00
SD	.53	14.09	53.65	71.74	58.10	29.29	14.96	2.65

TMT-A = Trail making test A; TMT-B = Trail making test B; TTT1 = Time to Task 1; TTT1 = Time to Task 2; TTT1 = Time to Task 3; SUS = System usability scale; NPS = Net promoter score. TMT-A, TMT-B and app navigation tasks are scored in seconds; the SUS score is out of 100; the NPS score is out of 10.

Table 3. Intercorrelation matrix for variables, age, cognitive tests and usability (Spearman’s rank order correlation).

Variables	1	2	3	4	5	6	7	8	9
1. Mini-Cog	-
2. Age	−.24	-
3. TMT_A	−.33	.27	-
4. TMT_B	−.42^*	.14	.63	-
5. TTT1	−.01	.18	.37	.25	-
6. TTT2	−.22	.25	.44^*	.54**	.09	-
7. TTT3	−.23	−.24	.12	.29	.25	.09	-
8. SUS	.51	−.24	−.25	−.38^*	.08	−.49**	−.35	-
9. NPS	.22	−.33	−.33	−.18	.20	−.41^*	.10	.70	-

TMT_A = Trail making test A; TMT_B = Trail making test B; TTT1 = Time to Task 1; TTT1 = Time to Task 2; TTT1 = Time to Task 3; SUS = System usability scale; nps = Net promoter score. TMT-A, TMT-B and Navigation tasks are scored in seconds; the SUS score is out of 100; the NPS score is out of 10.

Correlations between cognition and usability that are significant are displayed in bold text.

*p < .05, **p < .01.

Table 4. Cognitive tests and usability: analysis by age category (Mann Whitney).

		Cognitive tests (objective)			Task-based usability tests (objective)			Usability scores (subjective)
Age category		Mini-cog	TMT-A	TMT-B	TTT1	TTT2	TTT3	SUS	NPS
Younger (>75)	Mean Rank	16.07	12.50	11.93	12.25	13.32	15.18	16.93	16.29
Older (>75)	Mean Rank	12.93	16.50	17.07	16.75	15.68	13.82	12.07	12.71

TMT_A = Trail making test A; TMT_B = Trail making test B; TTT1 = Time to Task 1; TTT1 = Time to Task 2; TTT1 = Time to Task 3; SUS = System usability scale; NPS = Net promoter score.

Table 5. Usability: analysis by gender (Mann Whitney).

		Task-based usability tests (objective)			Usability scores (subjective)
Gender		TTT1	TTT2	TTT3	SUS	NPS
Males	Mean Rank	16.95	14.77	14.14	16.41	15.59
Females	Mean Rank	12.91	14.32	14.74	13.26	13.79

TMT_A = Trail making test A; TMT _B = Trail making test B; TTT1 = Time to Task 1; TTT1 = Time to Task 2; TTT1 = Time to Tas (Mannk 3; SUS = System usability scale; NPS = Net promoter score.

Table 6. Usability: analysis by education level (kruskal-wallis).

	Usability tests (objective)			Usability scores (subjective)
	TTT1	TTT2	TTT3	SUS	NPS
Median	78.50	73.00	43.50	77.500	8.00
Chi-Square	5.61	.20	4.67	2.21	3.05
Asymp. Sig.	.060	.904	.097	.331	.217

TMT_A = Trail making test A; TMT _B = Trail making test B; TTT1 = Time to Task 1; TTT1 = Time to Task 2; TTT1 = Time to Task 3; SUS = System usability scale; NPS = Net promoter score.

Figure 1. Recommendations for improving the app.

Data availability statement

Data will be made available from the first author.