Risk Analysis of Bankruptcy in the U.S. Healthcare Industries Based on Financial Ratios: A Machine Learning Analysis
Abstract
:1. Introduction
2. Literature Review
3. Objective
4. Data, Methodology, and Variables
4.1. Data Collection
4.2. Study Design and Machine Learning Analysis
4.3. Statistical Analysis
5. Results
6. Discussion
6.1. The High Robustness and Predictive Power of Gradient Boosting Machine Learning Algorithm
6.2. Important Financial Ratios Sensitive to Bankruptcy Prediction
6.3. Limitations and Future Directions
7. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
- Clement, C. Machine Learning in Bankruptcy Prediction—A Review. J. Public Adm. Financ. Law 2020, 17, 178–196. [Google Scholar]
- Geng, R.; Bose, I.; Chen, X. Prediction of financial distress: An empirical study of listed Chinese companies using data mining. Eur. J. Oper. Res. 2015, 241, 236–247. [Google Scholar] [CrossRef]
- Wessels, M. Predicting Financial Distress at Dutch General Hospitals: A Machine Learning Approach. Master’s Thesis, Utrecht University, Utrecht, The Netherlands, 2018. [Google Scholar]
- Beauvais, B.; Ramamonjiarivelo, Z.; Betancourt, J.; Cruz, J.; Fulton, L. The Predictive Factors of Hospital Bankruptcy—An Exploratory Study. Healthcare 2023, 11, 165. [Google Scholar] [CrossRef] [PubMed]
- Pendergast, P.M.; Sousa, M.D.; Wadsworth, T. Health Insurance and Bankruptcy Risk: Examining the Impact of the Affordable Care Act. Brook. L. Rev. 2020, 86, 975. [Google Scholar]
- Jones, B.D. The Government’s Perspective on Health Care Bankruptcies. Am. Bankruptcy Inst. J. 2018, 37, 22–23. [Google Scholar]
- Skinner, B.J. The Medical Bankruptcy Myth; Fraser Institute: Vancouver, BC, Canada, 2009. [Google Scholar]
- Shrime, M.G.; Weinstein, M.C.; Hammitt, J.K.; Cohen, J.L.; Salomon, J.A. Trading bankruptcy for health: A discrete-choice experiment. Value Health 2018, 21, 95–104. [Google Scholar] [CrossRef] [PubMed]
- Himmelstein, D.U.; Thorne, D.; Warren, E.; Woolhandler, S. Medical bankruptcy in the United States, 2007: Results of a national study. Am. J. Med. 2009, 122, 741–746. [Google Scholar] [CrossRef]
- Gross, T.; Notowidigdo, M.J. Health insurance and the consumer bankruptcy decision: Evidence from expansions of Medicaid. J. Public Econ. 2011, 95, 767–778. [Google Scholar] [CrossRef]
- Maizel, S.; Bernardino, C.; Caine, M.; Garfinkle, J. Corporate Bankruptcy Panel: The Healthcare Industry Post-Affordable Care Act: A Bankruptcy Perspective. Emory Bankr. Dev. J. 2014, 31, 249. [Google Scholar]
- Supriyanto, J.; Darmawan, A. The effect of financial ratio on financial distress in predicting bankruptcy. J. Appl. Manag. Account. 2018, 2, 110–120. [Google Scholar] [CrossRef]
- Amalia, S.; Fadjriah, N.E.; Nugraha, N.M. The influence of the financial ratio to the prevention of bankruptcy in cigarette manufacturing companies sub sector. Solid State Technol. 2020, 63, 4173–4182. [Google Scholar]
- Lee, B.-H.; Lee, S.-H. A study on financial ratio and prediction of financial distress in financial markets. J. Distrib. Sci. 2018, 16, 21–27. [Google Scholar]
- Tian, S.; Yu, Y. Financial ratios and bankruptcy predictions: An international evidence. Int. Rev. Econ. Financ. 2017, 51, 510–526. [Google Scholar] [CrossRef]
- Aly, S.; Alfonse, M.; Salem, A.-B.M. Bankruptcy prediction using artificial intelligence techniques: A survey. In Digital Transformation Technology: Proceedings of ITAF 2020, Online, 26–27 January 2021; Springer: Singapore, 2022; pp. 335–360. [Google Scholar]
- Sarker, I.H. Machine learning: Algorithms, real-world applications and research directions. SN Comput. Sci. 2021, 2, 160. [Google Scholar] [CrossRef] [PubMed]
- Rao, T.V.N.; Gaddam, A.; Kurni, M.; Saritha, K. Reliance on artificial intelligence, machine learning and deep learning in the era of industry 4.0. In Smart Healthcare System Design: Security and Privacy Aspects; John Wiley & Sons: Hoboken, NJ, USA, 2022; pp. 281–299. [Google Scholar]
- Huang, Y.-P.; Yen, M.-F. A new perspective of performance comparison among machine learning algorithms for financial distress prediction. Appl. Soft Comput. 2019, 83, 105663. [Google Scholar] [CrossRef]
- Roumani, Y.F.; Nwankpa, J.K.; Tanniru, M. Predicting firm failure in the software industry. Artif. Intell. Rev. 2020, 53, 4161–4182. [Google Scholar] [CrossRef]
- Smith, M.; Alvarez, F. Predicting firm-level bankruptcy in the Spanish economy using extreme gradient boosting. Comput. Econ. 2022, 59, 263–295. [Google Scholar] [CrossRef]
- Zelenkov, Y.; Fedorova, E.; Chekrizov, D. Two-step classification method based on genetic algorithm for bankruptcy forecasting. Expert Syst. Appl. 2017, 88, 393–401. [Google Scholar] [CrossRef]
- Schönfeld, J.; Kuděj, M.; Smrčka, L. Financial health of enterprises introducing safeguard procedure based on bankruptcy models. J. Bus. Econ. Manag. 2018, 19, 692–705. [Google Scholar] [CrossRef]
- Tsai, C.-F.; Hsu, Y.-F.; Yen, D.C. A comparative study of classifier ensembles for bankruptcy prediction. Appl. Soft Comput. 2014, 24, 977–984. [Google Scholar] [CrossRef]
- Alfaro, E.; García, N.; Gámez, M.; Elizondo, D. Bankruptcy forecasting: An empirical comparison of AdaBoost and neural networks. Decis. Support Syst. 2008, 45, 110–122. [Google Scholar] [CrossRef]
- Mai, F.; Tian, S.; Lee, C.; Ma, L. Deep learning models for bankruptcy prediction using textual disclosures. Eur. J. Oper. Res. 2019, 274, 743–758. [Google Scholar] [CrossRef]
- Antulov-Fantulin, N.; Lagravinese, R.; Resce, G. Predicting bankruptcy of local government: A machine learning approach. J. Econ. Behav. Organ. 2021, 183, 681–699. [Google Scholar] [CrossRef]
- Shetty, S.; Musa, M.; Brédart, X. Bankruptcy Prediction Using Machine Learning Techniques. J. Risk Financ. Manag. 2022, 15, 35. [Google Scholar] [CrossRef]
- Lahmiri, S.; Bekiros, S. Can machine learning approaches predict corporate bankruptcy? Evidence from a qualitative experimental design. Quant. Financ. 2019, 19, 1569–1577. [Google Scholar] [CrossRef]
- Kim, H.; Cho, H.; Ryu, D. Corporate bankruptcy prediction using machine learning methodologies with a focus on sequential data. Comput. Econ. 2022, 59, 1231–1249. [Google Scholar] [CrossRef]
- Liashenko, O.; Kravets, T.; Kostovetskyi, Y. Machine Learning and Data Balancing Methods for Bankruptcy Prediction. Ekonomika 2023, 102, 28–46. [Google Scholar] [CrossRef]
- Jan, C.-L. Financial information asymmetry: Using deep learning algorithms to predict financial distress. Symmetry 2021, 13, 443. [Google Scholar] [CrossRef]
- Zoričák, M.; Gnip, P.; Drotár, P.; Gazda, V. Bankruptcy prediction for small-and medium-sized companies using severely imbalanced datasets. Econ. Model. 2020, 84, 165–176. [Google Scholar] [CrossRef]
- Adosoglou, G.; Lombardo, G.; Pardalos, P.M. Neural network embeddings on corporate annual filings for portfolio selection. Expert Syst. Appl. 2021, 164, 114053. [Google Scholar] [CrossRef]
- Bazzana, F.; Bee, M.; Hussin Adam Khatir, A.A. Machine learning techniques for default prediction: An application to small Italian companies. Risk Manag. 2024, 26, 1. [Google Scholar] [CrossRef]
- Carmona, P.; Dwekat, A.; Mardawi, Z. No more black boxes! Explaining the predictions of a machine learning XGBoost classifier algorithm in business failure. Res. Int. Bus. Financ. 2022, 61, 101649. [Google Scholar] [CrossRef]
- Ben Jabeur, S.; Stef, N.; Carmona, P. Bankruptcy prediction using the XGBoost algorithm and variable importance feature engineering. Comput. Econ. 2023, 61, 715–741. [Google Scholar] [CrossRef]
- Lombardo, G.; Pellegrino, M.; Adosoglou, G.; Cagnoni, S.; Pardalos, P.M.; Poggi, A. Machine Learning for Bankruptcy Prediction in the American Stock Market: Dataset and Benchmarks. Future Internet 2022, 14, 244. [Google Scholar] [CrossRef]
- Adosoglou, G.; Park, S.; Lombardo, G.; Cagnoni, S.; Pardalos, P.M. Lazy network: A word embedding-based temporal financial network to avoid economic shocks in asset pricing models. Complexity 2022, 2022, 9430919. [Google Scholar] [CrossRef]
- Bragoli, D.; Ferretti, C.; Ganugi, P.; Marseguerra, G.; Mezzogori, D.; Zammori, F. Machine-learning models for bankruptcy prediction: Do industrial variables matter? Spat. Econ. Anal. 2022, 17, 156–177. [Google Scholar] [CrossRef]
- Liu, Y.; Zeng, Q.; Li, B.; Ma, L.; Ordieres-Meré, J. Anticipating financial distress of high-tech startups in the European Union: A machine learning approach for imbalanced samples. J. Forecast. 2022, 41, 1131–1155. [Google Scholar] [CrossRef]
- Papík, M.; Papíková, L. Impacts of crisis on SME bankruptcy prediction models’ performance. Expert Syst. Appl. 2023, 214, 119072. [Google Scholar]
- Liu, Q.; Shi, C.; Tse, Y.; Zhang, L. The impact of public health emergencies on small and medium-sized enterprises: Evidence from China. Glob. Financ. J. 2023, 58, 100892. [Google Scholar] [CrossRef]
- Tudose, M.B.; Avasilcai, S. A review of the research on financial performance and its determinants. In Innovation in Sustainable Management and Entrepreneurship: Proceedings of the 2019 International Symposium in Management (SIM2019), Timisoara, Romania, 25–26 October 2019; Springer: Cham, Switzerland, 2020; pp. 229–244. [Google Scholar]
- Najib, A.S.; Cahyaningdyah, D. Analysis of the bankruptcy of companies with Altman model and Ohlson model. Manag. Anal. J. 2020, 9, 243–251. [Google Scholar] [CrossRef]
- Sharma, S.; Bodla, B.S. Review and comparison of Altman and Ohlson model to predict bankruptcy of companies. ANVESAK 2022, 52, 30–36. [Google Scholar]
- Altman, E.I.; Iwanicz-Drozdowska, M.; Laitinen, E.K.; Suvas, A. Distressed firm and bankruptcy prediction in an international context: A review and empirical analysis of Altman’s Z-score model. SSRN Electron. J. 2014, 2536340. [Google Scholar] [CrossRef]
- Elviani, S.; Simbolon, R.; Riana, Z.; Khairani, F.; Dewi, S.P.; Fauzi, F. The Accuracy of the Altman, Ohlson, Springate and Zmejewski Models in Bankruptcy Predicting Trade Sector Companies in Indonesia. Bp. Int. Res. Crit. Inst. (BIRCI-J.) 2020, 3, 334–347. [Google Scholar] [CrossRef]
- Salimi, A.Y. Validity of Altmans Z-Score model in predicting Bankruptcy in recent years. Acad. Account. Financ. Stud. J. 2015, 19, 233. [Google Scholar]
- Ohlson, J.A. Financial ratios and the probabilistic prediction of bankruptcy. J. Account. Res. 1980, 18, 109–131. [Google Scholar] [CrossRef]
- Altman, E.I. Financial ratios, discriminant analysis and the prediction of corporate bankruptcy. J. Financ. 1968, 23, 589–609. [Google Scholar] [CrossRef]
- Altman, E.I.; Iwanicz-Drozdowska, M.; Laitinen, E.K.; Suvas, A. Financial distress prediction in an international context: A review and empirical analysis of Altman’s Z-score model. J. Int. Financ. Manag. Account. 2017, 28, 131–171. [Google Scholar] [CrossRef]
- Matenda, F.R.; Sibanda, M.; Chikodza, E.; Gumbo, V. Bankruptcy prediction for private firms in developing economies: A scoping review and guidance for future research. Manag. Rev. Q. 2022, 72, 927–966. [Google Scholar] [CrossRef]
- Armeanu, D.-S.; Cioaca, S.-I. An assessment of the bankruptcy risk on the Romanian capital market. Procedia-Soc. Behav. Sci. 2015, 182, 535–542. [Google Scholar] [CrossRef]
- Frino, A.; Jones, S.; Wong, J.B. Market behaviour around bankruptcy announcements: Evidence from the Australian Stock Exchange. Account. Financ. 2007, 47, 713–730. [Google Scholar] [CrossRef]
- Fauzi, R.; Wahyudi, I. The effect of firm and stock characteristics on stock returns: Stock market crash analysis. J. Financ. Data Sci. 2016, 2, 112–124. [Google Scholar] [CrossRef]
- Deng, P.L. The Effect of Trading Activity and Holdings Market Capitalization on Portfolio Performance. Int. J. Econ. Financ. 2018, 10, 1–18. [Google Scholar] [CrossRef]
- Gholampour, S. Impact of Nature of Medical Data on Machine and Deep Learning for Imbalanced Datasets: Clinical Validity of SMOTE Is Questionable. Mach. Learn. Knowl. Extr. 2024, 6, 827–841. [Google Scholar] [CrossRef]
- Waterstraat, M.G.; Dehghan, A.; Gholampour, S. Optimization of number and range of shunt valve performance levels in infant hydrocephalus: A machine learning analysis. Front. Bioeng. Biotechnol. 2024, 12, 1352490. [Google Scholar] [CrossRef] [PubMed]
- Barboza, F.; Kimura, H.; Altman, E. Machine learning models and bankruptcy prediction. Expert Syst. Appl. 2017, 83, 405–417. [Google Scholar] [CrossRef]
- Singh, S.G. The early indicators of financial failure: A study of bankrupt and solvent health systems. J. Healthc. Manag. 2008, 53, 333. [Google Scholar]
- Gholampour, S. Computerized biomechanical simulation of cerebrospinal fluid hydrodynamics: Challenges and opportunities. Comput. Methods Programs Biomed. 2021, 200, 105938. [Google Scholar] [CrossRef] [PubMed]
- Gholampour, S.; Deh, H.H.H. The effect of spatial distances between holes and time delays between bone drillings based on examination of heat accumulation and risk of bone thermal necrosis. Biomed. Eng. Online 2019, 18, 65. [Google Scholar] [CrossRef]
- Gholampour, S.; Droessler, J.; Frim, D. The role of operating variables in improving the performance of skull base grinding. Neurosurg. Rev. 2022, 45, 2431–2440. [Google Scholar] [CrossRef]
- Gholampour, S.; Hassanalideh, H.H.; Gholampour, M.; Frim, D. Thermal and physical damage in skull base drilling using gas cooling modes: FEM simulation and experimental evaluation. Comput. Methods Programs Biomed. 2021, 212, 106463. [Google Scholar] [CrossRef] [PubMed]
- Hosseini, S.S.; Yamini, B.; Ichkitidze, L.; Asadi, M.; Fernandez, J.; Gholampour, S. Enhanced ionic polymer–metal composites with nanocomposite electrodes for restoring eyelid movement of patients with ptosis. Nanomaterials 2023, 13, 473. [Google Scholar] [CrossRef]
- Hassanalideh, H.H.; Gholampour, S. Finding the optimal drill bit material and proper drilling condition for utilization in the programming of robot-assisted drilling of bone. CIRP J. Manuf. Sci. Technol. 2020, 31, 34–47. [Google Scholar] [CrossRef]
- Gholampour, S.; Hajirayat, K. Minimizing thermal damage to vascular nerves while drilling of calcified plaque. BMC Res. Notes 2019, 12, 338. [Google Scholar] [CrossRef] [PubMed]
- Gholampour, S. Feasibility of assessing non-invasive intracranial compliance using FSI simulation-based and MR elastography-based brain stiffness. Sci. Rep. 2024, 14, 6493. [Google Scholar] [CrossRef] [PubMed]
- Gholampour, S. Can magnetic resonance elastography serve as a diagnostic tool for gradual-onset brain disorders? Neurosurg. Rev. 2023, 47, 3. [Google Scholar] [CrossRef] [PubMed]
- Gholampour, S. Modeling and simulation of cerebrospinal fluid disorders. Front. Bioeng. Biotechnol. 2023, 11, 1331170. [Google Scholar] [CrossRef]
- Alzayed, N.; Eskandari, R.; Yazdifar, H. Bank failure prediction: Corporate governance and financial indicators. Rev. Quant. Financ. Account. 2023, 61, 601–631. [Google Scholar] [CrossRef]
# | Ratio Name | Formula | # | Ratio Name | Formula |
---|---|---|---|---|---|
1 | Earnings ratio | 21 | Price-to-operating-cash-flow ratio | (Market capitalization)/(Cash flow from operation) | |
2 | Price-to-earnings ratio | (Market price per share)/(Earning per share) | 22 | Book value per share | |
3 | Price-to-sale ratio | (Market cap)/(Total sale) | 23 | Liquidity ratio | (Current assets)/(Current liabilities) |
4 | Price-to-book ratio | (Market price per share)/(Book value per share) | 24 | Debt ratio | (Total debt)/(Total assets) |
5 | Earnings per share | (Net income)/(Number of outstanding shares) | 25 | Price-to-cash-flow ratio | (Market price per share)/(Cash flow per share) |
6 | Return on equity | (Net income)/(Shareholders’ equity) | 26 | Cash ratio | (Cash and cash equivalents)/(Current liabilities) |
7 | Return on assets | (Net income)/(Total assets) | 27 | Return on capital employed | (Operating profit)/(Capital employed) |
8 | Return on investment | (Net income)/(Cost of investment) | 28 | Return on sales | (Operating profit)/(Net sales) |
9 | Gross margin | (Gross profit)/Revenue | 29 | Cash return on invested capital | (Free cash flow)/(Invested capital) |
10 | Net margin | (Net profit)/Revenue | 30 | Cash return on equity | (Free cash flow)/(Shareholders’ equity) |
11 | Operating margin | (Operating income)/Revenue | 31 | Cash return on assets | (Free cash flow)/(Total assets) |
12 | Current ratio | (Current assets)/(Current liabilities) | 32 | Free cash flow margin | (Free cash flow)/(Total revenue) |
13 | Quick ratio | 33 | Operating cash flow margin | (Operating cash flow)/(Total revenue) | |
14 | Debt-to-equity ratio | Debt/(Shareholder’s equity) | 34 | Total asset turnover ratio | Revenue/(Average total assets) |
15 | Accounts receivable turnover ratio | (Net credit sales)/(Average account receivable) | 35 | Equity ratio | (Total equity)/(Total assets) |
16 | Operating cash flow ratio | (Cash from operations)/(Current liabilities) | 36 | Excess return | (Actual return)—(Required return) |
17 | EV-to-EBITDA ratio | (Enterprise value)/EBITDA | 37 | Fixed asset turnover ratio | (Net sales)/(Average fixed assets) |
18 | EV-to-sales ratio | (Enterprise value)/Sales | 38 | Receivables turnover ratio | (Net sales)/(Average account receivable) |
19 | EV-to-EBIT ratio | (Enterprise value)/EBIT | 39 | Total-liabilities-to-total-assets ratio | (Total liabilities)/(Total assets) |
20 | Price-to-free-cash-flow ratio | (Market capitalization)/(Free cash flow) | 40 | EBIT margin | EBIT/Revenue |
Financial Ratios | Mean | SE | p-Value | Financial Ratios | Mean | SE | p-Value |
---|---|---|---|---|---|---|---|
FR 1 | −7.35 | 1.93 | 0.0001 | FR 21 | −600.31 | 1417.46 | 0.6720 |
FR 2 | 1.66 | 11.78 | 0.8876 | FR 22 | 7.46 | 0.75 | 0.0000 |
FR 3 | 1241.45 | 587.43 | 0.0347 | FR 23 | 6.44 | 0.23 | 0.0000 |
FR 4 | 330,027.84 | 270,878.66 | 0.2233 | FR 24 | 0.18 | 0.01 | 0.0000 |
FR 5 | −7.35 | 1.93 | 0.0001 | FR 25 | −9.50 | 8.61 | 0.2701 |
FR 6 | −1.01 | 1.22 | 0.4117 | FR 26 | 2.64 | 0.09 | 0.0000 |
FR 7 | −0.55 | 0.03 | 0.0000 | FR 27 | −0.72 | 0.20 | 0.0002 |
FR 8 | 9.15 | 2.41 | 0.0001 | FR 28 | −32.28 | 3.94 | 0.0000 |
FR 9 | 0.50 | 0.03 | 0.0000 | FR 29 | 1.75 | 1.18 | 0.1396 |
FR 10 | −32.43 | 4.01 | 0.0000 | FR 30 | 1.63 | 1.62 | 0.3141 |
FR 11 | −32.28 | 3.94 | 0.0000 | FR 31 | −0.40 | 0.02 | 0.0000 |
FR 12 | 6.44 | 0.23 | 0.0000 | FR 32 | −27.71 | 3.52 | 0.0000 |
FR 13 | 3.94 | 0.07 | 0.0000 | FR 33 | −27.28 | 3.39 | 0.0000 |
FR 14 | −0.48 | 0.43 | 0.2664 | FR 34 | 0.38 | 0.02 | 0.0000 |
FR 15 | −46.13 | 18.83 | 0.0144 | FR 35 | 0.51 | 0.01 | 0.0000 |
FR 16 | −2.35 | 0.09 | 0.0000 | FR 36 | −0.43 | 0.01 | 0.0000 |
FR 17 | 8.40 | 6.88 | 0.0000 | FR 37 | 1.59 | 0.13 | 0.0000 |
FR 18 | 1651.01 | 586.73 | 0.0049 | FR 38 | −46.13 | 18.83 | 0.0144 |
FR 19 | 4.92 | 3.10 | 0.1124 | FR 39 | 0.49 | 0.01 | 0.0000 |
FR 20 | −0.34 | 0.17 | 0.0495 | FR 40 | −32.30 | 3.94 | 0.0000 |
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Gholampoor, H.; Asadi, M. Risk Analysis of Bankruptcy in the U.S. Healthcare Industries Based on Financial Ratios: A Machine Learning Analysis. J. Theor. Appl. Electron. Commer. Res. 2024, 19, 1303-1320. https://doi.org/10.3390/jtaer19020066
Gholampoor H, Asadi M. Risk Analysis of Bankruptcy in the U.S. Healthcare Industries Based on Financial Ratios: A Machine Learning Analysis. Journal of Theoretical and Applied Electronic Commerce Research. 2024; 19(2):1303-1320. https://doi.org/10.3390/jtaer19020066
Chicago/Turabian StyleGholampoor, Hadi, and Majid Asadi. 2024. "Risk Analysis of Bankruptcy in the U.S. Healthcare Industries Based on Financial Ratios: A Machine Learning Analysis" Journal of Theoretical and Applied Electronic Commerce Research 19, no. 2: 1303-1320. https://doi.org/10.3390/jtaer19020066
APA StyleGholampoor, H., & Asadi, M. (2024). Risk Analysis of Bankruptcy in the U.S. Healthcare Industries Based on Financial Ratios: A Machine Learning Analysis. Journal of Theoretical and Applied Electronic Commerce Research, 19(2), 1303-1320. https://doi.org/10.3390/jtaer19020066