A Longitudinal Study Examining Self-Regulation Practices in Older Drivers with and without Suspected Mild Cognitive Impairment

Figures & data

Table 1 Socio-Demographic Characteristics for Older Drivers with and without Suspected MCI at Baseline (n=670)

	No Cognitive Impairment (at Baseline)	Suspected MCI (at Baseline)	p-value
	(n=443)	(n=227)
	n (%)	n (%)
Gender			0.001*
Male	181 (40.86)	123 (54.19)
Female	262 (59.14)	104 (45.81)
Age Group			0.001*
65–69 years	143 (32.28)	55 (24.23)
70–74 years	170 (38.37)	73 (32.16)
≥75 years	130 (29.35)	99 (43.61)
Marital Status^a			0.828
Married/De facto	349 (79.14)	178 (78.41)
Single/Separated/Divorced/Widowed	92 (20.86)	49 (21.59)
Highest Education Achieved^a			0.251
Primary/Secondary	169 (38.15)	97 (42.73)
Higher Education	274 (61.85)	130 (57.27)
Living Arrangements^a			0.929
Alone	85 (19.23)	43 (18.94)
Not Alone	357 (80.77)	184 (81.06)
Number of Comorbidities			0.106
None	48 (10.84)	28 (12.33)
1–3	290 (65.46)	130 (57.27)
4+	105 (23.7)	69 (30.4)
Prescription Medication			0.097
No	94 (21.22)	36 (15.86)
Yes	349 (78.78)	191 (84.14)
Crashes (in the past year)^a			0.568
None	418 (94.57)	217 (95.59)
≥1	24 (5.43)	10 (4.41)
Traffic Infringements (in the past year)^a			0.877
None	386 (87.13)	197 (87.56)
≥1	57 (12.87)	28 (12.44)
License Restriction			0.979
No	390 (88.04)	200 (88.11)
Yes	53 (11.96)	27 (11.89)

Notes: ^aMissing information. *p<0.05.

Abbreviation: MCI, mild cognitive impairment.

Table 2 GEE Logistic Regression Models Assessing Changes in Self-Regulation Practices for Each Driving Situation from Baseline to One-Year Follow-Up for Drivers with and without Suspected MCI (n=670)

Driving Situation		OR*	95% CI		p-value
Driving when it is raining	No cognitive impairment	1
	Suspected MCI	1.08	0.76	1.53	0.670
Driving alone	No cognitive impairment	1
	Suspected MCI	1.15	0.38	3.55	0.803
Parallel parking	No cognitive impairment	1
	Suspected MCI	1.06	0.82	1.37	0.651
Making turns across oncoming traffic	No cognitive impairment	1
	Suspected MCI	1.60	1.02	2.53	0.041**
Driving on highways or freeways	No cognitive impairment	1
	Suspected MCI	1.42	0.72	2.78	0.307
Driving on heavy traffic roads	No cognitive impairment	1
	Suspected MCI	1.58	0.95	2.62	0.077
Driving during peak hour	No cognitive impairment	1
	Suspected MCI	1.08	0.8	1.47	0.601
Driving at night	No cognitive impairment	1
	Suspected MCI	1.24	0.91	1.69	0.167
Driving at night in the rain	No cognitive impairment	1
	Suspected MCI	1.11	0.9	1.37	0.330

Notes: *Univariate logistic odds ratio. **p<0.05.

Abbreviations: MCI, mild cognitive impairment; CI, confidence interval; OR, odds ratio.

Table 3 GEE Poisson Regression Model Assessing Changes in the Number of Situations Drivers with and without Suspected MCI Self-Regulated Their Driving, Over One Year (n=670)

	IRR	95% CI		p-value
Cognition
No cognitive impairment*	1
Suspected MCI	1.13	1.02	1.27	0.025**
Time
Baseline*	1
Follow-up	0.92	0.84	1.01	0.066
Gender
Male*	1
Female	1.87	1.52	2.32	0.001**
Age Group
65–69 years*	1
70–74 years	0.98	0.83	1.15	0.812
75+ years	1.33	1.10	1.60	0.003**
Marital Status^a
Married/De facto*	1
Single/Separated/Divorced/Widowed	0.98	0.83	1.17	0.860
Number of Comorbidities
None*	1
1–3	1.26	1.01	1.58	0.040**
4+	1.39	1.08	1.78	0.011**
Crashes
None*	1
≥1	1.03	0.82	1.30	0.811
Traffic Infringements
None*	1
≥1	0.80	0.67	0.95	0.011**
Change in Driving Confidence
Increase/No change*	1
Decrease	1.32	1.10	1.58	0.003**
Preference of transport
Drive self*	1
Someone else driving	1.38	1.12	1.70	0.003**

Notes: *Reference category. **p<0.05. ^aMissing information.

Abbreviations: MCI, mild cognitive impairment; IRR, incidence rate ratio; CI, confidence interval.