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Table 3 Rates of change in outcomes estimated by mixed effects model by sex and program status

From: Beat osteoporosis — nourish and exercise skeletons (BONES): a group randomized controlled trial in children

 

Rate of change of outcome (per year)

Males & Females

Males

Females

Outcome of each model

Group indicator a

Rate of change (unit/year)

Standard error

p-value vs. Ca

Rate of change (unit/year)

Standard error

p-value vs. Ca

Rate of change (unit/year)

Standard error

p-value vs. Ca

BMI z-score

B + P

0.02322

0.02401

0.1292

0.03198

0.04089

0.1886

0.01316

0.02422

0.4654

B

0.04661

0.03001

0.3969

0.08685

0.04747

0.6667

0.00321

0.03359

0.3984

C

0.08362**

0.03161

0.11626*

0.04888

0.04514

0.03636

Percent body fat (%)

B + P

1.3784**

0.4691

0.2319

1.7398**

0.5517

0.0265

1.1805*

0.4845

0.8099

B

1.8076**

0.5588

0.1021

2.2980***

0.6407

0.0076

1.8399**

0.6219

0.6313

C

0.4771

0.5882

−0.1397

0.6306

1.3871

0.7070

Calcium-rich food knowledge score

B + P

0.4788***

0.0855

0.9342

0.4306**

0.1425

0.8080

0.4897***

0.1151

0.7887

B

0.7524***

0.1097

0.0680

0.7004***

0.1660

0.3458

0.7848***

0.1572

0.1333

C

0.4672***

0.1104

0.4827**

0.1593

0.4345*

0.1706

Physical activity knowledge score

B + P

32.88***

8.27

0.5947

35.96**

12.58

0.5123

29.99**

10.95

0.9289

B

44.58***

10.56

0.2088

40.46**

15.14

0.4153

48.81**

14.72

0.3449

C

25.70*

10.64

23.43

14.33

28.26

15.92

Calcium-rich food preference score

B + P

0.1084

0.0619

0.8224

0.1353

0.0938

0.5823

0.0948

0.0835

0.8278

B

0.1088

0.0795

0.8375

0.0668

0.1115

0.9517

0.1313

0.1144

0.9816

C

0.0857

0.0800

0.0575

0.1053

0.1274

0.1240

Total calcium intake

B + P

−9.58

42.35

0.4939

−14.39

55.73

0.5383

−22.70

46.75

0.6603

B

15.62

52.08

0.7695

−33.04

65.98

0.4407

47.57

62.68

0.7301

C

37.75

54.57

37.68

63.32

14.79

71.10

Trimmed calcium intake (< 2500 for age up to 9, < 3000 for age > =9)

B + P

−6.44

38.28

0.3339

−20.00

50.79

0.2724

−7.26

44.34

0.7929

B

3.87

47.67

0.4653

−35.06

51.23

0.2377

24.60

59.38

0.9050

C

54.06

49.38

64.94

57.88

13.89

67.01

MET score

B + P

1.8873**

0.6772

0.0026

1.6754

1.0115

0.0039

2.0405*

0.8800

0.3259

B

0.8487

0.5874

0.0596

1.7086

1.2161

0.0076

−0.1833

1.1811

0.6910

C

−1.4592

0.8682

−2.8420*

1.1566

0.5103

1.2797

WBF score

B + P

0.4746***

0.1349

0.0019

0.5125*

0.2052

0.0010

0.4260*

0.1753

0.5584

B

0.2317

0.1708

0.0679

0.4448

0.2454

0.0046

0.0037

0.2349

0.4753

C

−0.2141

0.1731

− 0.5335*

0.2339

0.2445

0.2550

Grip strength (kg)

B + P

1.2406***

0.1461

0.6682

1.0568***

0.1802

0.9395

1.3980***

0.1709

0.4730

B

1.0055***

0.1787

0.6049

1.0356***

0.2122

0.9988

1.0197***

0.2244

0.6379

C

1.1391***

0.1861

1.0361***

0.2050

1.1789***

0.2522

Vertical jump (in)

B + P

0.6154***

0.1473

0.6493

0.6276***

0.1773

0.8487

0.5810**

0.1747

0.3824

B

0.2651

0.1780

0.0759

0.0243

0.2089

0.0601

0.5269*

0.2237

0.3414

C

0.7233***

0.1857

0.5761**

0.2027

0.8497**

0.2538

Bone stiffness

B + P

0.5682

0.8032

0.0506

−1.6887

1.4825

0.4189

2.0487*

0.8608

0.0995

index (3 groups)

B

−0.2319

1.1187

0.2368

−4.0010

2.0555

0.8523

2.0957

1.1986

0.1386

C

−2.0669

1.0574

−3.5066*

1.6495

−0.5761

1.3078

Bone stiffness

B + P/B

0.3026

0.6527

0.0603

−2.4862*

1.2067

0.6204

2.0757**

0.6990

0.0797

index (2 groups)

C

−2.0670

1.0584

−3.5101*

1.6554

−0.5754

1.3078

  1. Abbreviations: B + P BONES + Parent, B BONES, C Control, BMI body mass index, MET metabolic equivalent time, WBF weight-bearing factor
  2. Adjusted for time point, baseline age, and race/ethnicity (white, black, Hispanic, others); adjusted for individual nested within after-school program as cluster effects
  3. In total, 2476 observations were made in the three time points. Numbers of observations used in the above analysis range from 1828 (74%) to 1902 (77%) for all the outcomes except bone stiffness. For bone stiffness, the number of observation used in the analysis is 981 (40%)
  4. ap vs. C: p-value of the difference between the slopes of the intervention (B + P or B) and the control group
  5. * p < 0.05; ** p < 0.01; *** p < 0.001; these p-values indicate if the rate of change is significantly different from zero