Table 4

Prospective associations between mobile phone variables at baseline and mental health outcomes at 1-year follow-up

CURRENT STRESS

SLEEP DISTURBANCES

SYMPTOMS OF DEPRESSION

One item

SYMPTOMS OF DEPRESSION

Two items

n

Prev %

PR

95% CI

n

Prev %

PR

95% CI

n

Prev %

PR

95% CI

n

Prev %

PR

95% CI

Mobile phone use

Men

High

227

8

0.9

0.51-1.47

193

21

1.8

1.21-2.69

120

38

1.7

1.14-2.46

86

13

1.1

0.53-2.10

Medium

258

11

1.2

0.76-1.87

243

17

1.4

0.98-2.11

121

30

1.4

0.94-2.10

105

19

1.5

0.86-2.53

Low

652

10

1.0

596

13

1.0

333

23

1.0

305

15

1.0

Women

High

389

20

1.1

0.84-1.43

323

24

1.2

0.91-1.57

131

39

1.2

0.88-1.69

120

33

1.5

1.02-2.24

Medium

382

18

1.0

0.75-1.30

367

20

1.1

0.81-1.40

161

31

0.9

0.68-1.30

150

26

1.2

0.83-1.79

Low

968

19

1.0

909

19

1.0

435

33

1.0

370

22

1.0

Availability demands

Men

High

296

14

1.6

0.97-2.56

261

19

1.4

0.91-2.12

137

30

1.2

0.76-1.85

120

20

1.6

0.88-3.05

Medium

525

8

0.9

0.56-1.44

491

14

1.0

0.66-1.45

285

26

1.0

0.70-1.52

246

15

1.1

0.63-1.96

Low

314

9

1.0

280

15

1.0

152

26

1.0

131

14

1.0

Women

High

390

22

1.3

0.99-1.76

342

22

1.1

0.81-1.45

146

32

0.9

0.62-1.23

141

30

1.4

0.94-2.17

Medium

722

19

1.1

0.87-1.45

655

20

1.0

0.79-1.30

281

31

0.8

0.63-1.12

263

26

1.2

0.85-1.78

Low

625

17

1.0

599

19

1.0

299

37

1.0

235

20

1.0

Awakened at night

Men

High

138

13

1.4

0.80-2.42

116

21

1.4

0.90-2.31

57

32

1.1

0.68-1.94

48

19

1.4

0.65-2.86

Medium

516

10

1.1

0.71-1.60

462

15

1.0

0.74-1.47

264

27

1.0

0.74-1.45

225

15

1.0

0.63-1.65

Low

485

9

1.0

456

15

1.0

254

26

1.0

224

16

1.0

Women

High

268

22

1.2

0.86-1.60

229

23

1.2

0.87-1.68

96

39

1.2

0.84-1.81

78

24

1.1

0.62-1.80

Medium

791

17

0.9

0.70-1.12

740

20

1.1

0.86-1.39

324

33

1.0

0.78-1.34

299

28

1.3

0.90-1.77

Low

680

20

1.0

630

19

1.0

307

33

1.0

263

22

1.0

Accessibility stress

Men

High

80

19

2.2

1.22-3.80

94

23

1.7

1.06-2.71

25

24

0.9

0.40-2.14

27

30

2.3

1.06.4.98

Medium

317

11

1.3

0.88-2.01

288

16

1.2

0.84-1.69

145

32

1.3

0.89-1.79

123

20

1.6

0.96-2.56

Low

740

9

1.0

651

14

1.0

404

25

1.0

347

13

1.0

Women

High

176

32

2.2

1.61-3.00

181

27

1.5

1.10-2.14

54

43

1.3

0.82-2.03

58

47

2.4

1.50-3.68

Medium

677

21

1.5

1.15-1.85

645

21

1.2

0.96-1.54

280

35

1.1

0.84-1.42

241

24

1.2

0.82-1.63

Low

885

15

1.0

773

18

1.0

393

32

1.0

341

21

1.0

Over-use

Men

High

26

12

1.2

0.36-3.71

23

22

1.4

0.58.3.49

11

54

1.9

0.82-4.45

7

29

2.0

0.48-8.43

Medium

141

13

1.3

0.79-2.18

129

13

0.9

0.52-1.43

67

28

1.1

0.68-1.80

53

9

0.6

0.25-1.55

Low

953

10

1.0

866

16

1.0

484

26

1.0

428

16

1.0

Women

High

98

21

1.3

0.80-1.97

94

32

1.8

1.21-2.62

35

29

0.9

0.46-1.63

33

24

1.1

0.51-2.16

Medium

353

24

1.4

1.08-1.79

323

24

1.4

1.06-1.78

125

40

1.2

0.89-1.66

109

31

1.4

0.92-2.00

Low

1269

17

1.0

1163

18

1.0

560

33

1.0

491

23

1.0

Participants who reported symptoms at baseline were excluded from prospective analysis of mental health outcome concerned. Study group n in prospective analysis was for Current stress: 1222 men and 1913 women, Sleep disturbances: 1107 men and 1762 women, Symptoms of depression (one item): 617 men and 791 women, and Symptoms of depression (two items): 534 men and 692 women. Prevalence (prev %) of mental health symptoms at 1-year follow-up in each exposure category is shown. The prevalence ratios (PRs) with 95% confidence intervals (CIs) were adjusted for relationship status, educational level and occupation. Missing values (non-responses to items) were excluded from the analyses, which means that the n varied in the analyses. Prevalence ratios with a CI not including 1.00 are given in bold.

Thomée et al. BMC Public Health 2011 11:66   doi:10.1186/1471-2458-11-66