Table 4.

The Association of Weather Conditions and IMPAACT Participant Characteristics with Daily Accelerometer Counts: Mixed Effects Regression Results^*

4823 Daily Observations of 241 IMPAACT Participants, May 2006-May 2008

	B	SE	P
Intercept	21123	35463	0.53
Accelerometer Wear Hours	10292	739	<.0001
Weekend Day	−10687	2814	0.0001
Participant Characteristics
Rheumatoid Arthritis	Reference
Knee Osteoarthritis	24471	7835	0.002
Age<50	Reference
Age50–65	−39884	9076	<.0001
Age 66–75	−98029	11159	<.0001
Age >75	−176215	13751	<.0001
Female	Reference
Male	11436	8177	0.16
Employed Full or Part Time	−16430	7668	0.03
High School or less	Reference
Some College Education	−19912	12587	0.11
College Degree	−3167	8378	0.71
White/Other	Reference
African American	−16892	10443	0.11
Hispanic	−25950	13062	0.05
Current Smoker	10468	14074	0.46
Drinks Alcohol Regularly	−7368	7190	0.31
Underweight (BMI <=18.5)	−20190	23938	0.40
Normal Weight (BMI >18.5 and <24.99)	Reference
Overweight (BMI >24.99 and <29.99)	−7567	9627	0.43
Obese (BMI=>30)	−40038	9535	<.0001
SF-36 Physical Health Status Score (0–100)	2724	382	<.0001
SF-36 Mental Health Status Score (0–100)	1092	412	0.01
Weather Measures
Daylight Hours	5493	1630	0.001
No Precipitation	Reference
Precipitation 0.1–0.99”	−7333	3634	0.04
Precipitation ≥1”	−26000	7808	0.0009
No Snowfall	Reference
Snowfall 0.1–0.99”	9988	7120	0.16
Snowfall ≥1”	9136	6793	0.18
Moderate Day (20≤Mean Temperature<75)	Reference
Hot Day (Mean Temperature≥75)	−13255	5807	0.02
Cold Day (Mean Temperature <20)	−11002	5429	0.04

^*Adjusted for nesting of repeated measures for 241 participants with up to six weekly accelerometer wear waves.