[1] Hoogendijk EO, Afilalo J, Ensrud KE, et al. Frailty: implications for clinical practice and public health. Lancet, 2019; 394, 1365−75. doi:  10.1016/S0140-6736(19)31786-6
[2] Collard RM, Boter H, Schoevers RA, et al. Prevalence of frailty in community-dwelling older persons: a systematic review. J Am Geriatr Soc, 2012; 60, 1487−92. doi:  10.1111/j.1532-5415.2012.04054.x
[3] He B, Ma Y, Wang C, et al. Prevalence and risk factors for frailty among community-dwelling older people in China: a systematic review and meta-analysis. J Nutr Health Aging, 2019; 23, 442−50. doi:  10.1007/s12603-019-1179-9
[4] Wu SS, Yang ZR, Liu S, et al. Frailty status and risk of irritable bowel syndrome in middle-aged and older adults: a large-scale prospective cohort study. eClinicalMedicine, 2023; 56, 101807. doi:  10.1016/j.eclinm.2022.101807
[5] Fan JN, Yu CQ, Guo Y, et al. Frailty index and all-cause and cause-specific mortality in Chinese adults: a prospective cohort study. Lancet Public Health, 2020; 5, e650−60. doi:  10.1016/S2468-2667(20)30113-4
[6] Robertson DA, Savva GM, Kenny RA. Frailty and cognitive impairment-A review of the evidence and causal mechanisms. Ageing Res Rev, 2013; 12, 840−51. doi:  10.1016/j.arr.2013.06.004
[7] Sha S, Pan Y, Xu YB, et al. Associations between loneliness and frailty among older adults: evidence from the China health and retirement longitudinal study. BMC Geriatr, 2022; 22, 537. doi:  10.1186/s12877-022-03044-0
[8] Kojima G. Frailty as a predictor of disabilities among community-dwelling older people: a systematic review and meta-analysis. Disabil Rehabil, 2017; 39, 1897−908. doi:  10.1080/09638288.2016.1212282
[9] Sharma A, Hoover DR, Shi QH, et al. Frailty as a predictor of falls in HIV-infected and uninfected women. Antivir Ther, 2019; 24, 51−61. doi:  10.3851/IMP3286
[10] Clegg A, Young J, Iliffe S, et al. Frailty in elderly people. Lancet, 2013; 381, 752−62. doi:  10.1016/S0140-6736(12)62167-9
[11] Cao XQ, Li XQ, Zhang JY, et al. Associations between frailty and the increased risk of adverse outcomes among 38, 950 uk biobank participants with prediabetes: prospective cohort study. JMIR Public Health Surveill, 2023; 9, e45502. doi:  10.2196/45502
[12] Albert SM. The dynamics of frailty among older adults. JAMA Netw Open, 2019; 2, e198438. doi:  10.1001/jamanetworkopen.2019.8438
[13] García-Esquinas E, Rodríguez-Artalejo F. Environmental pollutants, limitations in physical functioning, and frailty in older adults. Curr Environ Health Rep, 2017; 4, 12−20. doi:  10.1007/s40572-017-0128-1
[14] Song QH, Dai M, Lin TP, et al. Biomass fuel usage for cooking and frailty among older adults in China: a population-based cohort study. Front Public Health, 2023; 11, 1122243. doi:  10.3389/fpubh.2023.1122243
[15] Balmes JR. Household air pollution from domestic combustion of solid fuels and health. J Allergy Clin Immunol, 2019; 143, 1979−87. doi:  10.1016/j.jaci.2019.04.016
[16] Vakalopoulos A, Dharmage SC, Dharmaratne S, et al. Household air pollution from biomass fuel for cooking and adverse fetal growth outcomes in rural sri lanka. Int J Environ Res Public Health, 2021; 18, 1878. doi:  10.3390/ijerph18041878
[17] Du XW, Li XZ, Qian P, et al. Indoor air pollution from solid fuels use, inflammation, depression and cognitive function in middle-aged and older Chinese adults. J Affect Disord, 2022; 319, 370−6. doi:  10.1016/j.jad.2022.09.103
[18] Bonjour S, Adair-Rohani H, Wolf J, et al. Solid fuel use for household cooking: country and regional estimates for 1980-2010. Environ Health Perspect, 2013; 121, 784−90. doi:  10.1289/ehp.1205987
[19] Balakrishnan K, Ramaswamy P, Sambandam S, et al. Air pollution from household solid fuel combustion in india: an overview of exposure and health related information to inform health research priorities. Glob Health Action, 2011; 4, 5638. doi:  10.3402/gha.v4i0.5638
[20] Fedarko NS. The biology of aging and frailty. Clin Geriatr Med, 2011; 27, 27−37. doi:  10.1016/j.cger.2010.08.006
[21] Ali MU, Yu YM, Yousaf B, et al. Health impacts of indoor air pollution from household solid fuel on children and women. J Hazard Mater, 2021; 416, 126127. doi:  10.1016/j.jhazmat.2021.126127
[22] Lee A, Kinney P, Chillrud S, et al. A systematic review of innate immunomodulatory effects of household air pollution secondary to the burning of biomass fuels. Ann Glob Health, 2015; 81, 368−74. doi:  10.1016/j.aogh.2015.08.006
[23] Feng R, Xu HM, He KL, et al. Effects of domestic solid fuel combustion emissions on the biomarkers of homemakers in rural areas of the fenwei plain, China. Ecotoxicol Environ Saf, 2021; 214, 112104. doi:  10.1016/j.ecoenv.2021.112104
[24] Jin XY, Wang YL, Wu YD, et al. The increased medical burden associated with frailty is partly attributable to household solid fuel: a nationwide prospective study of middle-aged and older people in China. Sci Total Environ, 2023; 858, 159829. doi:  10.1016/j.scitotenv.2022.159829
[25] Zhao YH, Hu YS, Smith JP, et al. Cohort profile: the China health and retirement longitudinal study (CHARLS). Int J Epidemiol, 2014; 43, 61−8. doi:  10.1093/ije/dys203
[26] Li CS, Zhou Y, Ding LY. Effects of long-term household air pollution exposure from solid fuel use on depression: evidence from national longitudinal surveys from 2011 to 2018. Environ Pollut, 2021; 283, 117350. doi:  10.1016/j.envpol.2021.117350
[27] Searle SD, Mitnitski A, Gahbauer EA, et al. A standard procedure for creating a frailty index. BMC Geriatr, 2008; 8, 24. doi:  10.1186/1471-2318-8-24
[28] Li CL, Ma YJ, Yang C, et al. Association of cystatin c kidney function measures with long-term deficit-accumulation frailty trajectories and physical function decline. JAMA Netw Open, 2022; 5, e2234208. doi:  10.1001/jamanetworkopen.2022.34208
[29] van Donkelaar A, Martin RV, Brauer M, et al. Global estimates of fine particulate matter using a combined geophysical-statistical method with information from satellites, models, and monitors. Environ Sci Technol, 2016; 50, 3762−72. doi:  10.1021/acs.est.5b05833
[30] van Donkelaar A, Martin RV, Li C, et al. Regional estimates of chemical composition of fine particulate matter using a combined geoscience-statistical method with information from satellites, models, and monitors. Environ Sci Technol, 2019; 53, 2595−611. doi:  10.1021/acs.est.8b06392
[31] Li TT, Zhang Y, Wang JN, et al. All-cause mortality risk associated with long-term exposure to ambient PM2·5 in China: a cohort study. Lancet Public Health, 2018; 3, e470−7. doi:  10.1016/S2468-2667(18)30144-0
[32] Cao LM, Zhao ZY, Ji C, et al. Association between solid fuel use and cognitive impairment: a cross-sectional and follow-up study in a middle-aged and older Chinese population. Environ Int, 2021; 146, 106251. doi:  10.1016/j.envint.2020.106251
[33] Shi WM, Zhang TT, Li YZ, et al. Association between household air pollution from solid fuel use and risk of chronic diseases and their multimorbidity among Chinese adults. Environ Int, 2022; 170, 107635. doi:  10.1016/j.envint.2022.107635
[34] Li W, Yuan DQ, Wang MX, et al. The effect of clean cooking on the social participation of middle-aged and older adults in China: a prospective cohort study. Sci Total Environ, 2024; 922, 171207. doi:  10.1016/j.scitotenv.2024.171207
[35] Nagin DS, Odgers CL. Group-based trajectory modeling in clinical research. Annu Rev Clin Psychol, 2010; 6, 109−38. doi:  10.1146/annurev.clinpsy.121208.131413
[36] Jones BL, Nagin DS, Roeder K. A SAS procedure based on mixture models for estimating developmental trajectories. Sociol Methods Res, 2001; 29, 374−93. doi:  10.1177/0049124101029003005
[37] van der Nest G, Lima Passos V, Candel MJJM, et al. An overview of mixture modelling for latent evolutions in longitudinal data: modelling approaches, fit statistics and software. Adv Life Course Res, 2020; 43, 100323. doi:  10.1016/j.alcr.2019.100323
[38] Li CX, Zhang DF, Pang XL, et al. Trajectories of perioperative serum tumor markers and colorectal cancer outcomes: a retrospective, multicenter longitudinal cohort study. eBioMedicine, 2021; 74, 103706. doi:  10.1016/j.ebiom.2021.103706
[39] Wu BJ, Fan BB, Qu YL, et al. Trajectories of blood lipids profile in midlife women: does menopause matter? J Am Heart Assoc, 2023; 12, e030388.
[40] Dahlqwist E, Zetterqvist J, Pawitan Y, et al. Model-based estimation of the attributable fraction for cross-sectional, case-control and cohort studies using the R package AF. Eur J Epidemiol, 2016; 31, 575−82. doi:  10.1007/s10654-016-0137-7
[41] Calderón-Larrañaga A, Hu XN, Haaksma M, et al. Health trajectories after age 60: the role of individual behaviors and the social context. Aging, 2021; 13, 19186−206. doi:  10.18632/aging.203407
[42] Du W, Wang JZ, Zhuo SJ, et al. Emissions of particulate PAHs from solid fuel combustion in indoor cookstoves. Sci Total Environ, 2021; 771, 145411. doi:  10.1016/j.scitotenv.2021.145411
[43] Fougère B, Vellas B, Billet S, et al. Air pollution modifies the association between successful and pathological aging throughout the frailty condition. Ageing Res Rev, 2015; 24, 299−303. doi:  10.1016/j.arr.2015.09.004
[44] Zhang JF, Smith KR. Household air pollution from coal and biomass fuels in China: measurements, health impacts, and interventions. Environ Health Perspect, 2007; 115, 848−55. doi:  10.1289/ehp.9479
[45] Hu K, Keenan K, Hale JM, et al. The association between city-level air pollution and frailty among the elderly population in China. Health Place, 2020; 64, 102362. doi:  10.1016/j.healthplace.2020.102362
[46] Lv YB, Yang Z, Ye LH, et al. Long-term fine particular exposure and incidence of frailty in older adults: findings from the Chinese Longitudinal Healthy Longevity Survey. Age Ageing, 2023; 52, afad009. doi:  10.1093/ageing/afad009
[47] Guo Z, Xue H, Fan LJ, et al. Differential effects of size-specific particulate matter on frailty transitions among middle-aged and older adults in China: findings from the China health and retirement longitudinal study (CHARLS), 2015-2018. Int Health, 2024; 16, 182−93. doi:  10.1093/inthealth/ihad033
[48] Wang Q, Fan J, Kwan MP, et al. Examining energy inequality under the rapid residential energy transition in China through household surveys. Nat Energy, 2023; 8, 251−63. doi:  10.1038/s41560-023-01193-z
[49] Hou BD, Liao H, Wang JW, et al. Cooking fuel decision-making and family structure: a field study in China. Environ Sci Pollut Res Int, 2019; 26, 24050−61. doi:  10.1007/s11356-019-05216-9
[50] Zhu X, Yun X, Meng WJ, et al. Stacked use and transition trends of rural household energy in mainland China. Environ Sci Technol, 2019; 53, 521−9. doi:  10.1021/acs.est.8b04280
[51] Li CS, Zhou Y. Residential environment and depressive symptoms among Chinese middle- and old-aged adults: a longitudinal population-based study. Health Place, 2020; 66, 102463. doi:  10.1016/j.healthplace.2020.102463
[52] Shi SM, Olivieri-Mui B, McCarthy EP, et al. Changes in a frailty index and association with mortality. J Am Geriatr Soc, 2021; 69, 1057−62. doi:  10.1111/jgs.17002
[53] McCarron A, Uny I, Caes L, et al. Solid fuel users' perceptions of household solid fuel use in low- and middle-income countries: a scoping review. Environ Int, 2020; 143, 105991. doi:  10.1016/j.envint.2020.105991